THE 

GAS     ENGINEER'S 

POCKET-BOOlt 

COMPRISING 
BELATING    TO 

THE  MANUFACTURE,  DISTRIBUTION,  AND  USE  OF  COAL  GAS 

AND 

THE  CONSTRUCTION  OF  GAS  WORKS 
BY 

HENKY    O'CONNOE 

FELLOW  OF  THE  ROYAL   SOCIETY,    EDINBURGH 

ASSOCIATE    MEMBER   OF  THE   INSTITUTION  OF  CIVIL  ENGINEERS 
PAST  PRESIDENT  OF  THE   SOCIETY   OF   ENGINEERS 

THIRD  EDITION,  REVISED 


LONDON 

CROSBY    LOCKWOOD     AND     SON 

7,  STATIONERS'  HALL  COURT,  LUDGATE  HILL 

1907 


Library 


BIIADBURY,   AONXW,  *    CO.  LD.,  POINTERS, 
LONDON  AND  TONBRIDOK. 


TO    HIS    OLD    CHIEFS 

CORBET  WOODALL,  ESQ.,  M.lNST.C.E. 

SIR    GEORGE    LIVESEY,    M.lNST.C.E. 

GEORGE  CARELESS  TREWBY,  ESQ.,  M.lNST.C.E. 

IN  ACKNOWLEDGMENT  OF  MUCH  VALUABLE   INFOEMATION   RECEIVED 

FROM  THEM  BY  THE   AUTHOR  DURING  HIS   WORK 

UNDER  THEIR  DIRECTION 

HENRY  O'CONNOR 


274327 


PREFACE. 


IN  placing  this  compilation  before  his  readers — and  in 
particular,  his  brother  Engineers  of  the  Gas  Industry — it 
may  not  be  out  of  place  for  the  Author  to  indicate  the 
circumstances  which  have  led,  in  the  first  instance,  to 
the  preparation  of  the  Tables,  Notes,  and  other  matter 
comprised  in  the  volume,  and  now  to  their  issue  in  the 
present  form. 

Having  frequently  during  the  course  of  his  professional 
career  experienced  the  want  of  any  book  containing  those 
numerous  tables,  data,  &c.,  which,  with  the  spread  of 
engineering  knowledge,  are  every  day  becoming  more  and 
more  necessary  to  the  Gas  Engineer  for  reference,  he  has 
for  many  years  been  in  the  habit  of  making  and  preserving, 
for  his  own  use,  full  notes  from  every  available  source. 
These  notes  have  formed  the  basis  of  the  present  work,  and 
the  fact  that  they  were  originally  intended  only  for  his 
own  personal  use  has  rendered  it  in  many  cases  well-nigh 
impossible  for  the  Author  to  acknowledge  the  sources  of 
his  information.  He  desires,  however,  to  express  here  his 
indebtedness  to  both  the  Journal  of  Gas  Lighting  and  the 
Gas  World,  whose  full  and  careful  reports,  given  from  time 
to  time,  of  papers  read  and  discussions  held  at  the  various 
meetings  of  Engineering  Societies,  at  which  questions  con- 
cerning the  Gas  Industry  have  been  under  review,  have 
afforded  him  the  means  of  obtaining  a  considerable  portion 
of  the  matter  here  presented. 


VI  PKEFACE. 

In  deciding  the  plan  upon  which  the  matter  should  be 
arranged,  it  appeared  to  the  Author  that  the  most  suitable 
method  was  to  take  the  various  processes  consecutively  as 
they  occur  in  the  course  of  Gas-making,  and  to  treat  of  the 
Construction  of  the  Works  separately  from  the  Manufacture 
of  the  Gas. 

The  diagrammatic  form  of  tabulating  has  been  followed 
wherever  it  seemed  to  be  preferable,  and  the  dimensions 
of  the  volume  have  in  consequence  been  increased  from  the 
ordinary  pocket-book  size,  so  as  to  enable  the  diagrams 
to  be  better  seen  and  read. 

The  Tables  have  been  most  carefully  checked,  and  every 
precaution  taken  to  render  them  as  accurate  as  possible. 
Should,  however,  any  error  be  detected  in  them,  the  Author 
will  feel  much  obliged  for  information  of  the  fact ;  while  he 
will  welcome  any  communication  upon  the  subject  generally 
with  which  readers  may  be  pleased  to  favour  him. 

H.  O'C. 

Edinburgh,  1897. 


NOTE  TO   THIRD   EDITION. 

IT  is  very  gratifying  that  another  edition  of  the  POCKET- 
BOOK  has  been  speedily  called  for,  and  the  opportunity  has 
been  taken  of  amending  and  supplementing  the  text  of  the 
book  where  advisable,  and  of  bringing  the  Statutory  Regula- 
tions for  Testing  the  Illuminating  Power  and  Purity  of  Gas 
up  to  date,  as  revised  August,  1906. 


TABLE  OF  CONTENTS. 

GENERAL  CONSTRUCTING    MEMORANDA. 
General  Mathematical  Tables. 

PAGE 

Squares,  Cubes,   Square  Roots,  Cube  Roots,   Reciprocals   and 

Logarithms 1 

Logarithms,  description  of 23 

Area  and  Circumferences  of  Circles  in  £  hs,  ^ths,  and  ^ths    .  24 

Properties  of  Circles .         .     .  41 

Weights  and  Measures 42 

Decimals  of  £1,  cwt.,  mile,  year,  inch,  foot,  lb.,  ton       .        .     .  45 

Equivalent  English  and  Metric  Weights  and  Measures      .        .  56 

Cubic  Feet  into  Cubic  Metres,  and  the  reverse      .                 .     .  58 

Sizes  of  Drawing  Paper,  and  Colours  used  in  Drawings      .         .  59 

Weights  of  Materials 60 

Foundations 64 

Footings 65 

Damp  Courses  and  Inverted  Arches 66 

Brickwork  notes 67 

„          Courses  (diagrams) 70 

Scaffolding  notes 72 

Strength  of  Mortar 72 

Portland  Cement  notes 73 

Facing  and  Pointing 74 

Resistance  to  Crushing 75 

Stonework  notes 76 

Painting  notes 76 

Glazing  notes .         .         .  77 

Roof  Coverings .     .  78 

Proportions  of  Treads  and  Risers  to  Staircases  .        .        .        .81 


Viii  CONTENTS. 

X>AGE 

Timber  notes 81 

Breaking  Loads  on  Wooden  Pillars  (diagram)      ....      84 
Safe  Loads  on  Wooden  Beams  and  Joists        .        ,        .        .     85,  86 

Dead  and  Live  Loads 87 

Water  Power,  Specific  Heats 88 

Radiant  Heat 89 

Factors  of  Safety ft        .     .       89 

Weight  of  Flat  Rolled  Iron 90 

Birmingham  and  American  Gauges 96 

Weight  of  Zinc,  Thickness  of  Tin  Plates      .        .       :.        .        .      96 
Tin-Plates,  Dimensions  and  Weights       .        ..       ,        .       .-.».    .       97 

Copper  Nails 98 

Corrugated  Iron  Roof  Sheeting 98 

Electrical  Conductivity  and  Melting  Point  of  Metals          .        .       98 

Castings 99 

Case- Hardening 100 

Breaking  Strength,  Elastic  Strength,  and  Modulus  of  Elasticity     101 

Proportions,  Strengths,  and  Weights  of  Bolts,  Nuts,  and  Washers     102 

„  and  Strengths  of  Riveted  Joints          .         .         .     .     104 

Strengths,  and  Weights  of  Rivets    .        .         .        .106 

Strengths  of  Ropes  and  Chains .     109 

Testing  Iron  and  Steel          .         .        .  '/.   .     .        .         .        .113 

Weights  of  Cast  Iron  Pipes 115 

Average  Dimensions  of  Socket  and  Flanged  Connections    .     116,  118 

Diagrams  of  Weight  of  Cast  Iron  Pipes 120 

Proportions  of  Pipe  Flanges 122 

Weight  of  Lead  and  Composition  Pipes  ...  •     123 

Whitworth  Screw  Threads    .        .        .        .'_.'."  .125 

Weights  of  Sheet  Metals  (diagram)       ,  .        .  \   .        .        •     •     128 
Weight  of  Half-round  Iron  end  Sheet  Brass        .....     .         .     130 

Weight  of  Round  and  Square  Iron  and  Steel  .         .         ...     131 

Wrought  Iron  Girders 132 

Diagram  of  proper  Size  of  Rolled  Joists  ...  .     .     134 

Moments  of  Inertia  and  Resistance  of  Beams       .  .136 

Girders 138 

Plates .        .    140 

Least  Radius  of  Gyration 141 

Arches 143 

Unloading  Materials  and  Storage  (Construction). 

Space  required  by  different  Coals 145 

Coal  Stores 145,  148 


CONTENTS.  IX 

PAGE 

Stabling  and  Koads 146 

Railways  and  Locomotives 148 

Crane  Hooks    . 150 


Retort  House  (Construction). 

Hydraulic  Cranes 151 

Conveyors  and  Grabs 152 

Fire-Clays  and  Bricks 152 

Retorts 153 

Dimensions  of  Retort  Houses      .        .        .         .        .        .        .154 

Settings 155 

Hydraulic  Mains .         •         .159 

Ascension  Pipes 160 

Hydraulic  Main  Valves 161 

Connections  in  Gas  Works 162 


Condensers  (Construction). 

Dimensions  necessary 163 

General  notes 163 

Loss  of  Heat  in  Air  and  under  Water 164 

Deposition  of  Tar 165 

Tar  and  Liquor  Tanks          . 165 


Boilers,  Engines,  Pumps,  and  Exhausters  (Construction). 

Horse-power  and  Space  required     ....                 .     .  166 

„           „      for  24-inch  Pressure 167 

„           „       to  pass  Gas 167 

Steam  Pressures 169 

Losses  in  Boilers  and  Electric  Plants 169 

Proportions  of  Boilers 170 

Strength             „ 171 

Safety  Valves .176 

Boiler  Chimneys 176 

Lightning  Conductors      ..." 181 

Steam  and  Exhaust  Pipes 182 

Distance  between  Bearings  of  Shafts  (diagram)     .                 .     .  183 

Notes  on  Pumps 184 

Flywheels  and  Toothed  Gearing 187 

Belt  Gearing 188 


X  CONTENTS. 

PAGE 

Rope  Gearing  .        .        . 189 

Gas  Engines 190 

Values  of  Explosive  Mixtures 193 

Scrubbers  and  Washers  (Construction). 

Dimensions  necessary  .        .        .        .        *      .  .      ,-.        .        .195 

Absorptive  Power  of  Water    .        .        .        .     ;.>-;    .        .     .  196 

Reaction  of  Cyanides  .        .       _.....  «*;-,,*        •        •  196 

Purifiers  (Construction). 

Area  required  .        .        .        .        ..       .                .        .        .     .  197 

Arrangements  of  Purifier  Connections        .        .;       «-<    •        •  199 

Claus  Process  .        .        .        .        .        ...     .*•*•>•  i*7  ;r>:      .    .  201 

Gasholder  Tanks  (Construction). 

General  notes  and  Natural  Slopes  of  Earths        .  ".-'    ...  202 

Resistance  of  Earth  Backing  .        .        ...         .        .     .  204 

Formula  for  Strength  of  Tank  Walls  .        .        .        .";'.-    .  205 

Pressure  of  Water  against  a  Tank  Side                     .      -  . :   :;/    .  206 

Thickness  of  Sheets  for  Wrought  Iron  Tanks  (diagram)    .         .  208 

Concrete  Tank  Walls      .        .        j^ 209 

Gasholders  (Construction). 

General  notes       .        .        .        .  -•  :;,*^7      /*?  ,^n<i.  rr.  210 

Strains  on  Top  Sheets      .         .         •  i. /•<».'••••    «>  ]     ^     ,   •     •  211 

Rivets  required  for  different  Thicknesses  of  Plates     .  .      .         .  212 

Force  of  the  Wind  .        ,        .        .        ."","....'.."..         .     -  215 

Allowance  for  Wind  and  Snow    .        .        .        .    '  !_. ......'/-'.  217 

Guide  Framing  notes     -« 220 

Diagram  of  Pressures  thrown  by  Holders   .         .        ,      •.  .  .      .  221 

Formulae  for  Multipost  Gasholders         .        »        ...      .         ...  222 

„           Cantilever        „              .,        ..        .,        ....   /     .  223 

Notes  on  Cups  and  Grips        ...        ..        ..        ./      v  im>S;       •     •  ^^ 

Strains  on  Gasholder  Sheeting    .        ,        ^     €.-     .  •        •        •  225 

Workshop  Notes. 

Station  Meters 229 

„          „      General  Dimensions 230 


CONTENTS.  atl 

MANUFACTURING. 
Storing  Materials. 

PAGE 

Stacking  Coal          .                         231 

Igniting  Point  of  various  Coals 232 

Retort  House  (Working) 

Carbonising  notes 233 

Effects  of  Temperature  on  Distillation 235 

Make  of  Gas  per  Hour 237 

Climatic  Effects  on  Carbonisation 239 

Generator  Furnaces 240 

Regenerator  Furnaces 241 

Labour  required  for  Carbonising 245 

Curing  Stopped  Ascension  Pipes 246 

Table  of  Effects  of  Heat 247 

Pyrometers 249 

Residuals  from  Coal        .        . 251 

Gas  from  different  Substances 253 


Condensing  Gas. 

General  notes 255 

Tests  for  Napthalene 256 


•Exhausters,  &c. 

Effects  of  Air  on  Gas 258 

Combustion  of  Fuels  in  Boilers   .  ,,...,  259 

Boiler  Incrustations        .  ....  261 

Test  for  Pure  Water    ....  .  261 

Washing  ana  Scrubbing. 

Quantity  of  Ammonia  removed 262 

General  notes ...  263 

Cyanogen ...  265 


xii  CONTENTS. 

Purification. 

PAGE 

Analyses  of  Oxides 267 

Notes  on  Oxide  Purification 269 

„       Lime            „ .  270 

Kemoval  of  Sulphur  Compounds 272 

„           Carbon  Dioxide 272 

WeldonMud 274 

Revivification  in  situ 275 

Oxygen  in  Purification 276 

Arresting  Cyanogen  Compounds 277 

Composition  of  Purified  Illuminating  Gas 277 


Gasholders  (Care  of). 

Diffusion  of  Gases 279 

Painting  notes 279 


Distributing  Gas. 

Flow  of  Gases  through  Pipes 281 

Diagrams  of  Distributing  Power  of  Pipes 282 

Lead  required  for  Jointing 285 

Dimensions  of  Pipes 286 

Jointing  Material .  .  .  288 

Dimensions  of  Socket  Joints 289 

Testing  Mains 291 

Rack  and  Pinion  Valves 293 

Service  Pipes '  .  .  .  .  .  296 

Wrought  Iron  Tubing 297 

Diagram  of  Comparative  Pressures 299 

Napthalene HOI 

Cold  Enrichers 301 

Diagram  of  the  Number  of  Cubic  Feet  per  Id.  for  different 

prices  per  1,000  Cubic  Feet 303 

Diagram  of  Comparison  of  Prices  of  Gas  in  Sterling  and  French 

Moneys 304 

Relative  Values  of  Illuminating  Agents  .  ...  305 

Vitiation  of  Air 307 

Height  of  Lamps 309 


CONTENTS.  xiii 

PAGE 

Ventilation  notes 311 

Comparative  Costs  of  different  Lights 313 

Gas  Stove  notes 314 

Warming  by  Steam 315 

Heats  of  Fires 317 

Balloons 318 

Wet  Meters .     .  319 

Dry  Meters  .                 320 


Testing. 

Elementary  Bodies 322 

Air.  Gas,  and  Water .        .  323 

Saturated  Hydrocarbons 325 

Tension  of  Aqueous  Vapour 327 

Explosive  Mixtures         .........  329 

Lbs.  Water  heated  and  C02  produced 331 

Expansion  and  Weight  of  Water 333 

Melting  Points 334 

Boiling  Points .  335 

Specific  Heats 336 

Freezing  Mixtures 337 

Radiation  of  Heat 339 

Heat  Units  evolved  by  different  Substances 341 

To  Prepare  Chemical  Indicators 342 

„         Normal  Solutions 344 

TwaddeU 346 

Burners 348 

Composition  of  Coal  Gas 349 

Comparative  Analysis  of  Coal  and  Carburetted  Water  Gas    .     .  352 

Values  of  Illuminating  Gases 353 

Illuminating  Values  of  Hydrocarbons 355 

Temperatures  of  Flames 357 

Photometers 358 

„           general  notes 360 

Diagram  for  Correcting  for  Irregular  Burning  of  Candles      .     .  362 

Gas.        .        .  364 

„       of  Tabular  Numbers 366 

„       for  Correcting  for  Tabular  Numbers    ....  368 

Harcourt's  1- Candle  Pentane  Unit 369 

Hefner  Unit                                                                                     .  370 


CONTENTS. 


Dibdin's  10- Candle  Unit          .        .        .        .      t  .        .        .     .  371 
To  Test  Lime        .         .         .         .         .         .         .'                .         .372 

„       Oxide 373 

Ten  per  cent.  Acid  Solution 375 

Diagram  for  use  with  Harcourt's  Colour  Test          .        .         .     .  377 

Specific  Gravities  of  Gases  .        .        .        .....        .  379 

Testing  Coals  .        .        .        .        .        .        .        .        .        .    .  380 

Diagrams  showing  actual  Grains  Sulphur  from  Grains  BaS04    .  383 

Enriching  Processes. 

Cost  of  Enrichment     .         .         ...        .        .        .        .  385 

Benzol  as  an  Enricher    .         .        .        .        .        >»:,"<•   ,     •    •  387 

Acetylene     .        .        .        .        .        .        .'       -*rXv   '-••  •        •  39° 

Carburetted  Water  Gas  Plant          .        .         .     '   .         .         .     .  393 

Calorific  Value  of  Water  Gas       .  ~ "   .     , 399 

Dowson  Gas     .        .        .        .        .        .     '.'';"       .        ...  400 

Peebles  Process   .        .        .      js  .^ ',-- ,vl  '  -        •        •        .402 

Suction  Gas  Producer     .        .        .                403 

Products  Works. 

Sulphate  Making '        •        v        •         •    .  404 

Coal  Tar  Products -    5 , .•;  n  •         -406 

Analysis  of  Coal  Tar f  v, 

Supplementary. 

Statutory  and  Official  Regulations  for  Testing  the  Illuminating 

Power  and  Purity  of  Gas .         .         .        .        .;      s.,     _  .        .  410 

Notification  of  Gas  Referees  for  1906      .        .        .        ...  412 

Ten-candle  Pentane  Lamp    .        . 
The  Table  Photometer     . 

The  Metropolitan  Argand  No.  2 425 

Tabular  Numbers     .        .        .        .*  '     .*       A^-s\l       .        .    .  426 

Test  for  Sulphuretted  Hydrogen 428 

The  Gas  Calorimeter 430 

Gas  Referees'  Standard  Burner 435 

Table  giving  Illuminating  Power  of  Gas 436 

English,  French  and  German  Glossary  of  Terms  used  in  Gas 

Works    . 437 


THE 


GAS    ENGINEEK'S 

POCKET-BOOK. 


GENERAL    MATHEMATICAL    TABLES. 


No. 

Square.  ;    Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

1 

1 

1 

i-ooo 

1-000 

1-000000 

000000 

301030 

2 

4 

8 

1-414 

1-259 

•500000 

301030 

176091 

3 

9 

27 

1-732 

1-442 

•333333 

477121 

124939 

4 

16 

64 

2-000 

1-587 

•250000 

602060 

96910 

5 

25 

125 

2-236 

1-709 

•200000 

698970 

79181 

6 

36 

216 

2-449 

1-817 

•166667 

778151 

66947 

7 

49 

343 

2-645 

1-912 

•142857 

845098 

57992 

8 

64 

512 

2-828 

2-000 

•125000 

903090 

51153 

9 

81 

729 

3-000 

2-080 

•111111 

954243 

45757 

10 

100 

1,000 

3-162 

2-154 

•100000 

000000 

41393 

11 

121 

1,331 

3-316 

2-223 

•090909 

041393 

37788 

12   144 

1,728 

3-464 

2-289 

•083333 

079181 

34762 

13 

169 

2,197 

3-605 

2-351 

•076923 

113943 

32185 

14 

196 

2,744 

3-741 

2-410 

•071429 

146128 

29963 

15 

225 

3,375 

3-872 

2-466 

•066667 

176091 

28029 

16 

256 

4,096 

4-000 

2-519 

•062500 

204120 

26329 

17 

289 

4,913 

4-123 

2-571 

•058824 

230449 

24824 

18 

324 

5,832 

4-242 

2-620 

•055556 

255273 

23481 

19 

361 

6,859 

4-358 

2-668 

•052632 

278754 

22276 

20 

400 

8,000 

4-472 

2-714 

•050000 

301030 

21189 

21 

441 

9,261 

4-582 

2-758 

•047619 

322219 

20204 

22 

484 

10,624 

4-690 

2-802 

•045455 

342423 

19305 

23 

529 

12,167 

4-795 

2-843 

•043478 

361728 

18483 

24 

576 

13,824 

4-898 

2-884 

•041667 

380211 

17729 

25 

625 

15,625 

5-000 

2-924 

•040000 

397940 

17033 

26 

676 

17,676 

5-099 

2-962 

•038462 

414973 

16391 

27 

729 

19,683 

5-196 

3-000 

•037037 

431364 

15794 

28 

784 

21,952 

5-291 

3-036 

•035714 

447158 

15240 

29 

841 

24,389 

5-385 

3-072 

•034483 

462398 

14723 

G.E. 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

30 

900 

27,000 

5-477 

3-107 

•033333  477121 

14241 

31 

961 

29,791 

5-567 

3-141 

•032258  491362 

13798 

32 

1,024 

32,768 

5-656 

3-175 

•031250  505150 

13364 

33 

1,089 

35,937 

5-744 

3-207 

•030303  018514 

12965 

34 

1,156 

39,304 

5-830 

3-239 

•029412  531479 

12589 

35 

1,225 

42,875 

5-916 

3-271 

•028571  544068 

12235 

36 

1,296 

46,656 

6-000 

3-301 

•027778  556303 

11899 

37 

1,369 

50.653 

6-082 

3-332 

•027027  568202 

11582 

38 

1,444 

54,872 

6-164 

3-361 

•026316  579784 

11281 

39 

1,521 

59,319 

6-244 

3-391 

•025641 

£91065 

10995 

40 

1,600 

64,000 

6-326 

3-419 

•025000 

602060 

10724 

41 

1,681 

68,921 

6-403 

3-448 

•024390 

612784 

10465 

42 

1,764 

74,088 

6-480 

3-476 

•023810 

623249 

10219 

43 

1.849 

79,507 

6-557 

3-503 

•023256 

633468 

9985 

44 

1,936 

85,184 

6-633 

3-530 

•022727 

643453 

9760 

45 

2,025 

91,125 

6-708 

3-556 

•022222 

653213 

9545 

46 

2,116 

97,336 

6-782 

3-583 

•021739 

662758 

9340 

47 

2,209 

103,823 

6-855 

3-608 

•021277 

672098 

9143 

48 

2,304 

110,592 

6-928 

3-634 

•020833 

681241 

8955 

49 

2,401 

117,649 

7-000 

3-659 

•020408 

690196 

8774 

50 

2,500 

125,000 

7-071 

3-684 

•020000 

698970 

8600 

51 

2,601 

132,651 

7-141 

3-708 

•019608 

707570 

8433 

52 

2,704 

140,608 

7-211 

3-732 

•019231 

716003 

8273 

53 

2,809 

148,877 

7-280 

3-756 

•018868 

724276 

8118 

54 

2,916 

157,464 

7-348 

3-779 

•018519 

732394 

7969 

55 

3,025 

166,375 

7-416 

3-802 

•018182 

740363 

7825 

56 

3,136 

175,616 

7-483 

3-825 

•017857 

748188 

7687 

57 

3,249 

185,193 

7-549 

3-848 

•017544 

755875 

7553 

58 

3,364 

195,122 

7-615 

3-870 

•017241 

763428 

7424 

59 

3,481 

205,379 

7-681 

3-892 

•016949 

770852 

7299 

60 

3,600 

216,000 

7-745 

3-914 

•016667 

778151 

7179 

61 

3,721 

226,981 

7-810 

3-936 

•016393 

785330 

7062 

62 

3,844 

238,328 

7-874 

3-957 

•016129 

792392 

6949 

63 

3,969 

250,047 

7-937 

3-979 

•015873 

799341 

6839 

64 

4,096 

262,144 

8-000 

4-000 

•015625 

806180 

6733 

65 

4.225 

274,625 

8-062 

4-020 

•015385 

812913 

6631 

66 

4,356 

287,496 

8-124 

4-041 

•015152 

819544 

6531 

67 

4,489 

300,763 

8-185 

4-061 

•014925 

826075 

6434 

68 

4,624 

314,432 

8-246 

4-081 

•014706 

832509 

6340 

69 

4,761 

328,509 

8-306 

4-101 

•014493 

838849 

6249 

70 

4,900 

343,000 

8-366 

4-121 

•014286 

845098 

6160 

71 

5,041 

357,911 

8-426 

4-140 

•014085 

851258 

6074 

72 

5,184 

373,248 

8-485 

4-160 

•013889 

857332 

5991 

73 

5,329 

389,017 

8-544 

4-179 

•013699  863323 

5909 

74 

5,476 

405,224 

8-602 

4-198 

•013514  869232   5829 

GENERAL  MATHEMATICAL   TABLES. 


„  •,      Square 

Cube 

Recip- 

Loga- 

Differ- 

No. 

Square. 

Root. 

Root. 

rocal. 

rithm. 

ence. 

75 

5,625 

421,875 

8-660 

4-217 

•013333 

875061 

5753 

76 

5,776 

438,976 

8-717 

4-235 

•013158 

880814 

5677 

77 

5,929 

456,533 

8-744 

4-254 

•012987 

886491 

5604 

78 

6,084 

474,552 

8-831 

4-272 

•012821 

892095 

5532 

79 

6,241 

493,039 

8-888 

4-290 

•012658 

897627 

5463 

80 

6,400 

512,000 

8-944 

4-308 

•012500 

903090 

5395 

81 

6,561 

531,441 

9-000 

4-326 

•012346 

908485 

5329 

82 

6,724 

551,368 

9-055 

4-344 

•012195 

913814 

5264 

83 

6,889 

571,787 

9-110 

4-362 

•012048 

919078 

5201 

84   7,056 

592,704 

9-165 

4-379 

•011905 

924279 

5140 

85   7,225 

614,125 

9-219 

4-396 

•011765 

929419 

5079 

86 

7,396 

636,056 

9-273 

4-414 

•011628 

934498 

5021 

87 

7,569 

658,503 

9-327 

4-431 

•011494 

939519 

4964 

88 

7.744 

681,472 

9-380 

4-447 

•011364 

944483 

4907 

89 

7/J21 

704,969 

9-433 

4-461 

•011236 

949390 

4853 

90 

8,100 

729,000 

9-486 

4-481 

•011111 

954243 

4798 

91 

8,281 

753,571 

9-539 

4-497 

•010989 

959041 

4747 

92 

8,464 

778,688 

9-591 

4-514 

•010870 

963788 

4695 

93 

8,649 

804,357 

9-643 

4-530 

•010753 

968483 

4645 

94 

8,836 

830,584 

9-695 

4-546 

•010638 

973128 

4596 

95 

9.025 

857.375 

9-746 

4-562 

•010526 

977724 

4547 

96 

9.216 

884,786 

9-797 

4-578 

•010417 

982271 

4501 

97 

9,409 

912,673 

9-848 

4-594 

•010309 

986772 

4454 

98 

9,604 

941,192 

9-899 

4-610 

•010204 

991226 

4409 

99 

9,801 

970,299 

9-949 

4-626 

•010101 

995635 

4360 

100 

10,000 

1,000,000 

10-000 

4-641 

•010000 

000000 

4321 

101 

10,201 

1,030,301   10-049 

4-657 

•009901 

004321 

4279 

102 

10,404 

1,061,208   10-099 

4-672 

•009804 

008600 

4237 

103 

10,609 

1.092,727 

10-148 

4-687 

•009709 

012837 

4196 

104 

10,816 

1,124,864 

10-198 

4-702 

•009615 

017033 

4156 

105 

11,025 

1,157,625   10-246 

4-717 

•009524 

021189 

4117 

106 

11,236 

1,191,016  '10-295 

4-732 

•009434 

025306 

4078 

107 

11,449 

1,225,043   10-344 

4-747 

•009346 

029384 

4040 

108 

11,664 

1,259,712  110-392 

4-762 

•009259 

033424 

4002 

109 

11,881 

1,295,029 

10-440 

4-776 

•009174 

037426 

3967 

110 

12,100 

1.331,000 

10-488 

4-791 

•009091 

041393 

3930 

111 

12,321 

1,367,631 

10-535 

4-805 

•009009 

045323 

3895 

112 

12,554 

1,404,928 

10-583 

4-820 

•008929 

049218 

3860 

113 

12,769 

1,442,897 

10-630 

4-834 

•008850 

053078 

3827 

114 

12,996 

1,481,544 

10-677 

4-848 

•008772 

056905 

3793 

115 

13,225 

1,520,875 

10-723 

4-862 

•008696 

060698 

3760 

116 

13,456 

1,560,896 

10-770 

4-876 

•008621 

064458 

3728 

117 

13,689 

1,601,613 

10-816 

4-890 

•008547 

068186 

3696 

118 

13,924 

1,643,032 

10-862 

4-904 

•008475 

071882 

3665 

119 

14,161 

1,685,159 

10-908 

4-918 

•008403 

075547 

3634 

B  2 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

pnhA     Square 
Cube-     Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

120 

14,400 

1,728,000   10-954 

4-932 

•008333 

079181 

3604 

121 

14,641 

1,771,561   11-000 

4-946 

•008264 

082785 

3575 

122 

14,884 

1,815,848   11-045 

4-959 

•008197 

086360 

3545 

123 

15,129 

1,860,867   11-090 

4-973 

•008130 

089905 

3517 

124 

15,376 

1,906,624   11-135 

4-986 

•008065 

093422 

3488 

125 

15,025 

1,953,125   11-180 

5-000 

•008000 

096910 

3461 

126 

15,876 

2,000,376   11-224 

5-013 

•007937 

100371 

3433 

127 

16,129 

2,048,383   11-269 

5-026 

•007874 

103804 

3406 

128 

16,384 

2,097,152  ;11-313 

5-039 

•007813 

107210 

3380 

129 

16,641 

2.146,689  jll-357 

5-052 

•007752 

110590 

3343 

130 

16,900 

2,197,000 

11-401 

5-065 

•007692 

113943 

3328 

131 

17,161 

2,248,091 

11-445 

5-078 

•007634 

117271 

3303 

132 

17.424 

2,299,968 

11-489 

5-091 

•007576 

120574 

3278 

133 

17.689 

2,352,637 

11-532 

5-104 

•007519 

123852 

3253 

134 

17^56 

2,406,104 

11-575 

5-117 

•007463 

127105 

3229 

135 

18,225 

2,460,375 

11-618 

5-129 

•007407 

130334 

3205 

136 

18,496 

2,515,456 

11-661 

5-142 

•007353 

133539 

3182 

137 

18,769 

2,571,353 

11-704 

5-155 

•007299 

136721 

3148 

138 

19,044 

2,620,872 

11-747 

5-167 

•007246 

139879 

3136 

139 

19,321 

2,685,619 

11-789 

5-180 

•007194 

143015 

3113 

140 

19,600 

2,744,000 

11-832 

5-192 

•007143 

146128 

3091 

141 

19,881 

2,803,221 

11-874 

5-204 

•007092 

149219 

3069 

142 

20,164 

2,863,288 

11-916 

5-217 

•007042 

152288 

3048 

143 

20,449 

2,924,207 

11-958 

5-229 

•006993 

155336 

3026 

144 

20,736 

2,985,984 

12-000 

5-241 

•006944 

158362 

3006 

145 

21,025 

3,048,625 

12-041 

5-253 

•006897 

161368 

2985 

146 

21,316 

3,112,136 

12-083 

5-265 

•006849 

164353 

2964 

147 

21,609 

3,176,523 

12-124 

5-277 

•006803 

167317 

2945 

148 

21,904 

3,241,792 

12-165 

5-289 

•006757 

170262 

2924 

149 

22,201 

3,307,949 

12-206 

5-301 

•006711 

173186 

2905 

150 

22.500 

3,375,000 

12-247 

5-313 

•006667 

176091 

2886 

151 

22.X01 

3,442,951 

12-288 

5-325 

•006623 

178977 

2867 

152 

23.104 

3,511,808 

12-328 

5-336 

•006579 

181844 

2847 

153 

23,409 

3,581,577 

12-369 

5-348 

•006536 

184691 

2830 

154 

23,716 

3,652,264 

12-409 

5-360 

•006494 

187521 

2811 

155 

24,025 

3,723,875 

12-449 

5-371 

•006452 

190332 

2793 

156 

24,336 

3,796,416 

12-489 

5-383 

•006410 

193125 

2775 

157 

24,649 

3,869,893 

12-529 

5-394 

•006369 

195900 

2757 

158 

24,964 

3,944,312 

12-569 

5-406 

•006329 

198657 

2740 

159 

25,281 

4,019,679 

12-609 

5-417 

•006289 

201397 

2723 

160 

25,600 

4,096,000 

12-649 

5-428 

•006250 

204120 

2706 

161 

25,921 

4,173,281 

12-688 

5-440 

•006211 

206826 

2689 

162 

26,244 

4,251,528 

12-727 

5-451 

•006173 

209515 

2673 

163 

26,569 

4,330,747 

12-767 

5-462 

•006135 

212188 

2656 

164 

26,896 

4,410,944 

12-806 

5-473 

•006098 

214844 

2640 

GENERAL   MATHEMATICAL   TABLES. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

165 

27,225 

4,492,125 

12-845 

5-484 

•006061 

217484 

2624 

166 

27,556 

4,574,296 

12-884 

5-495 

•006024 

220108 

2608 

167 

27,889 

4,657,463 

12-922 

5-506 

•005988 

222716 

2583 

168 

28,224 

4,741,632 

12-961 

5-517 

•005952 

225309 

2578 

169 

28,561 

4,826,809 

13-000 

5-528 

•005917 

227887 

2562 

170 

28,900 

4,913,000 

13-038 

5-539 

•005882 

230449 

2547 

171 

29,241 

5,000,211 

13-076 

5-550 

•005848 

232996 

2532 

172 

29,584 

5,088,448 

13-114 

5-561 

•005814 

235528 

2518 

173 

29,929 

5,177,717 

13-152 

5-572 

•005780 

238046 

2503 

174 

30,276 

5,268,024 

13-190 

5-582 

•005747 

240549 

2489 

175 

30,625 

5,359,375 

13-228 

5-593 

•005714 

243038 

2475 

176 

30,976 

5,451,776 

13-266 

5-604 

•005682 

245513 

2460 

177 

31,329 

5,545,233 

13-304 

5-614 

•005650 

247973 

2447 

178 

31,684 

5,639,752 

13-341 

5-625 

•005618 

250420 

2433 

179 

32,041 

5,735,339 

13-379 

5-635 

•005587 

252853 

2420 

180 

32,400 

5,832,000 

13-416 

5-646 

•005556 

255273 

2406 

181 

32,761 

5,929,741 

13-453 

5-656 

•005525 

257679 

2392 

182 

33,124 

6,028,568 

13-490 

5-667 

•005495 

260071 

2380 

183 

33,489 

6,128,487 

13-527 

5-677 

•005464 

262451 

2367 

184 

33,856 

6,229,504 

13-564 

5-687 

•005435 

264818 

2354 

185 

34,225 

6,331,625 

13-601 

5-698 

•005405 

267172 

2341 

186 

34,596 

6,434,856 

13-638 

5-708 

•005376 

269513 

2329 

187 

34,969 

6,539,203 

13-674 

5-718 

•005348 

271842 

2316 

188 

35,344 

6,644,672 

13-711 

5-728 

•005319 

274158 

2304 

189 

35,721 

6,751,269 

13-747 

5-738 

•005291 

276462 

2292 

190 

36,100 

6,859,000 

13-784 

5-748 

•005263 

278754 

2279 

191 

36,481 

6,967,871 

13-820 

5-758 

•005236 

281033 

2268 

192 

36,864 

7,077,888 

13-856 

5-768 

•005208 

283301 

2256 

193 

37,249 

7,189,057 

13-892 

5-778 

•005181 

285557 

2245 

194 

37,636 

7,301,384 

13-928 

5-788 

•005155 

287802 

2233 

195 

38,025 

7,414,875 

13-964 

5-798 

•005128 

290035 

2221 

196 

38,416 

7,529,536 

14-000 

5-808 

•005102 

292256 

2210 

197 

38,809 

7,645,373 

14-035 

5-818 

•005076 

294466 

2199 

198 

39,204 

7,762,392 

14-071 

5-828 

•005051 

296665 

2188 

199 

39,601 

7,880,599 

14-106 

5-838 

•005025 

298853 

2177 

200 

40,000 

8,000.000 

14-142 

5-848 

•005000 

301030 

2166 

201  40,401 

8,120,601 

14-177 

5-857 

•004975 

303196 

2155 

202!  40,804 

8,242,408 

14-212 

5-867 

•004950  305351 

2145 

203 

41,209 

8,365,427 

14-247 

5-877 

•004926  307496 

2134 

204 

41,616 

8,489,664 

14-282 

5-886 

•004902 

309630 

2124 

205 

42,025 

8,615,125 

14-317 

5-896 

•004878 

311754 

2113 

206 

42,436 

8,741,816 

14-352 

5-905 

•004854 

313867 

2103 

207 

42,849 

8,869,743 

14-387 

5-915 

•004831 

315970 

2093 

208 

43,264 

8,998,912 

14-422 

5-924 

•004808 

318063 

2083 

209 

43,681 

9,123,329 

14-456 

5-934 

•004785 

320146 

2073 

GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

210 

44,100 

9.201,000 

14-491 

5-943 

•004702 

322219 

2003 

211 

44,521 

9^393,931 

14-525 

5-953 

•004739 

324282 

2054 

212 

44,944 

9,528,128 

14-500 

5-902 

•004717 

320336 

2044 

213 

45,309 

9,003,597 

14-594 

5-972 

•004095 

328380 

2034 

214 

45,790 

9,800,344 

14-028 

5-981 

•0046-73 

330414 

2024 

215 

40,225 

9,938,375 

14-002 

5-990 

•004651 

332438 

2010 

216 

40,050 

10,077,090 

14-090 

o-ooo 

•004630 

334454 

2006 

217 

47,089 

10,218.813 

14-730 

0-009 

•004608 

336460 

1996 

218 

47,524 

10,300,232 

14-704 

0-018 

•004587 

338450 

19S8 

219 

47,901 

10,503,459 

14-798 

0-027 

•004500 

340444 

197'.) 

220 

48,400 

10.048,000 

14-832 

0-030 

•004545 

342423 

19(51) 

221 

48,841 

10,793,801 

1400-8 

6-045 

•004525 

344392 

1961 

222 

49,284 

10,941,048 

14-899 

0-055 

•004505 

340353 

1952 

223 

49,729 

11,089,507 

14-933 

0-004 

•004484 

348305 

1943 

224 

50,170 

11,239,424 

14-960 

0-073 

•004404 

350248 

1935 

225 

50,025 

11,390,025 

15-000 

0-082 

•004444 

352183 

1925 

226 

51,070 

11,543.170 

15-033 

0-091 

•004425 

354108 

1918 

227 

51,529 

11,097,083 

15-000 

o-ioo 

•004405 

350020 

1909 

228 

51,984 

11,852.352 

15-099 

0-109 

•004380 

357935 

1900 

229 

52,441 

12,008,989 

15-132 

0-118 

•004307 

359835 

1893 

230 

52,900 

12,107,000 

15-105 

0-120 

•004348 

301728 

1884 

231 

53,301 

12,320,391 

15-198 

0-135 

•004329 

303612 

1870 

232 

53,824 

12,487,108 

15-231 

6-144 

•004310 

305488 

1808 

233 

54,289 

12,049,337 

15-204 

0-153 

•004292 

367356 

1800 

234 

54,750 

12,812,904 

15-297 

0-102 

•004274 

309216 

1852 

235 

55,225 

12,977,875 

15-329 

0-171 

•004255 

371068 

1844 

236 

55,090 

13,144,256 

15-302 

0-179 

•004237 

372912 

1830 

237 

50,109 

13,312,053 

15-394 

6-188 

•004219 

374748 

1829 

238 

50,044 

13,481,272 

15-427 

0-197 

•004202 

370577 

1821 

239 

57,121 

13,651,919 

15-459 

0-205 

•004184 

378398 

1813 

240 

57,000 

13,824,000 

15-491 

0-214 

•004107 

380211 

1800 

241 

58,081 

13,997,521 

15-524 

0-223 

•004149 

382017 

1798 

242 

58,504 

14,172,488 

15-550 

0-231 

•004132 

383815 

1791 

243 

59,049 

14,348,907 

15-588 

0-240 

•004115 

385000 

1784 

244 

59,530 

14,520,784 

15-020 

0-248 

•004098 

387390 

1  770 

245 

00,025 

14,700,125 

15-052 

6-257 

•004082 

389100 

1709 

246 

00,510 

14,880,930 

15-084 

6-265 

•004005 

390935 

1702 

247 

01,009 

15,009,223 

15-710 

6-274 

•004049 

392097 

1755 

248 

01,504 

15,252,992 

15-748 

6-282 

•004032 

394452 

1747 

249 

02,001 

15,438,249 

15-779 

6-291 

•004010 

390199 

1741 

250 

02.500 

15,025,000 

15-811 

6-299 

•004000 

397940 

1734 

251 

63,001 

15,813,251 

15-842 

6-307 

•003984 

399074 

1727 

252 

03,504 

10,003,008 

15-874 

6-316 

•003908 

401401 

17-20 

253 

04,009 

10,194,277 

15-905 

6-324 

•003953 

403121 

1713 

254 

64,510 

10,387,064 

15-937 

6-333 

•003937 

404834 

1700 

GENERAL    MATHEMATICAL    TABLES. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

255 

65,025 

16,581,375 

15-968 

6-341 

•003922 

406540 

1700 

256 

65,536 

16,777,216 

16-000 

6-349 

•003906 

408240 

1693 

257 

66,049 

16,974,593 

16-031 

6-357 

•003891 

409933 

1687 

258 

66,564 

17,173,512 

16-062 

6-366 

•003876 

411620 

1680 

259 

67,081 

17,373,979 

16-093 

6-374 

•003861 

413300 

1673 

260 

67,600 

17,576,000 

16-124 

6-382 

•003846 

414973 

1668 

231 

68,121 

17,779,581 

16-155 

6-390 

•003831 

416641 

1660 

262 

68,644 

17.984,728 

16-186 

6-398 

•003817 

418301 

1655 

263 

69.1(59 

18;i91,447 

16-217 

6-406 

•003802 

419956 

1648 

264 

69,^96 

18,399,744 

16-248 

6-415 

•003788 

421604 

1642 

2651  70.225 

18,609,625 

16-278 

6-423 

•003774 

423246 

1636 

266 

70,756 

18,821,096 

16-309 

6-431 

•003759 

424882 

1629 

267 

71,289 

19,034,163 

16-340 

6-439 

•003745 

426511 

1624 

268 

71,824 

19,248,832 

16-370 

6-447 

•003731 

428135 

1617 

269 

72,361 

19.465,109 

16-401 

6-455 

•003717 

429752 

1612 

270 

72,900 

19,683,000 

16-431 

6-463 

•003704 

431364 

1605 

271 

73,441 

19,902,511 

16-462 

6-471 

•003690 

432969 

1600 

272 

73,984 

20,123,648 

16-492 

6-479 

•003676 

434569 

1594 

273 

74,529 

20,346,417 

16-522 

6-487 

•003663 

436163 

1588 

274 

75,076 

20,570,824 

16-552 

6-495 

•003650 

437751 

1582 

275 

75,625 

20,796,875 

16,583 

6-502 

•003636 

439333 

1576 

276 

76,176 

21,024,576 

16-613 

6-510 

•003623 

440909 

1571 

277 

76,729 

21,253,933 

1C-643 

6-518 

•003610 

442480 

1  565 

278 

77,284 

21,484,952 

16-673 

6-526 

•003597 

444045 

1559 

279 

77,841 

21,717,639 

16-703 

6-534 

•003584 

445604 

1554 

280 

78,400 

21,952,000 

16-733 

6-542 

•003571 

447158 

1548 

281 

78,961 

22,188,041 

16-763 

6-549 

•003559 

448706 

1543 

282 

79,524 

22,425,768 

16-792 

6-557 

•003546 

450249 

1537 

283 

80,089 

22,665,187 

16-822 

6-565 

•003534 

451786 

1532 

284 

80,656 

22,906,304 

16-852 

6-573 

•003522 

453318 

1527 

285 

81,225 

23,149,125 

16-881 

6-580 

•003509 

454845 

1521 

286 

81,796 

23,393,656 

16-911 

6-588 

•003497 

456366 

1516 

287 

82,369 

23,639,903 

16-941 

6-596 

•008484 

457882 

1510 

288 

82,944 

23,887,872 

16-970 

6-603 

•003472 

459392 

1506 

289 

83,521 

24,137,569 

17-000 

6-611 

•003460 

460898 

1500 

290 

84,100 

24,389,000 

17-029 

6-619 

•003448 

462398 

1495 

291 

84,681 

24,642,171 

17-059 

6-627 

•003436 

463893 

1490 

292 

85,264 

24,897,088 

17-088 

6-634 

•003425 

465383 

1485 

293 

85,849 

25,153,757 

17-117 

6-642 

•003413 

466868 

1479 

294 

86,436 

25,412,184 

17-146 

6-649 

•003401 

468347 

1475 

295 

87,025 

25,672,375 

17-176 

6-657 

•003390 

469822 

1470 

296 

87,616 

25.934.336 

17-205 

6-664 

•003378 

471292 

1464 

297 

88,209 

26^98,073 

17-234 

6-672 

•003367 

472756 

1460 

298 

88,804 

26,463,592 

17-263 

6-679 

•003356 

474216 

1455 

299 

89,401 

26,730,899 

17-292 

6-687 

•003344 

475671 

1450 

GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square  Cube 
Root.  |  Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

300 

90.000 

27,000,000 

17-320 

6-694 

•003333 

477121 

1415 

301 

90,601 

27,270,901 

17-349 

6-702 

•003322 

478566 

1441 

302 

91,204 

27,543,608 

17-378 

6-709 

•003311 

480007 

143(5 

303 

91,809 

27,818,127 

17-407 

6-717 

•003301 

481443 

1431 

304 

92,416 

28,094,464 

17-436 

6-724 

•003289 

482874 

142(5 

305 

93,025 

28,372,625 

17-464 

6-731 

•OOH279 

484300 

1421 

306 

93,636 

28,652,616 

17-493 

6-739 

•003268 

485721 

1417 

307 

94,249 

28,934,443 

17-521 

6-74(5 

•003257 

487138 

1413 

308 

94,864 

29,218,112 

17-549 

6.753 

•003247 

488551 

1407 

309 

95,481 

29,503,629 

17-578 

6-761 

•003236 

489958 

1404 

310 

96,100 

29,791,000 

17-607 

6-768 

•003226 

491362 

1398 

311 

96,721 

30,080,231 

17-635 

6-775 

•003215 

492760 

1395 

312 

97,344 

30,371.328 

17-663 

6-782 

•003205 

494155 

1389 

313 

97,969 

30,664,297 

17-692  !  6-781) 

•003195 

495544 

1386 

314 

98.596 

30,959,144  ;  17-720 

6-797 

•003185 

496930 

1381 

315 

99,225 

31,255,875  1  17,748 

6-804 

•003175 

498311 

1376 

316 

99,856 

31,554,496 

17-776 

6-811 

•003165 

499687 

1372 

317 

100,489 

31,855,013 

17-804 

6-818 

•003155 

501059 

1368 

318 

101,124 

32,157,432 

17-832 

6-826 

•003145 

502427 

1364 

319 

101,761 

32,461,759 

17-860 

6-833 

•003135 

503791 

1359 

320 

102,400 

32,768,000 

17-888 

6-839 

•003125 

505150 

1355 

321 

103,041 

33,076,161 

17-916 

6-847 

•003115 

506505 

1351 

322 

103.684 

33,886,248 

17-944 

6-854 

•003106 

507856 

1347 

323 

104,329 

33,698,267 

17-972 

6-861 

•003096 

509203 

1342 

324 

104,976 

34,012.224 

18-000 

6-868 

•003086 

510545 

1338 

325 

105,625 

34,328,125 

18-028 

6-875 

•003077 

511883 

1335 

326 

106,276 

34,645,976 

18-055 

6-882 

•003067 

513218 

1330 

327 

106,929 

34,965,783 

18-083 

6-889 

•003058 

514548 

1326 

328 

107,584 

35.287,552 

18-111 

6-896 

•003049 

515874 

1322 

329 

108,241 

35,611,289 

18-138 

6-903 

•003040 

517196 

1318 

330 

108,900 

35,937.000 

18-166 

6-910 

•003030 

518514 

1314 

331 

109,561 

36,264,691 

18-193 

6-917 

•003021 

519828 

1310 

332 

110,224 

36,594,368  |18'221 

6-924 

•003012 

521138 

1306 

333 

110,889 

36,926,037  118-248 

6-931 

•003003 

522444 

1302 

334 

111,556 

37,259,704  18-276 

6-938 

•002994 

523746 

1299 

335 

112,225 

37,595,375  18'303 

6-945 

•002985 

525045 

1294 

336 

112,896 

37.933,056  18-330 

6-952 

•002976 

526339 

1291 

337 

113,569 

38,272,753  18-357 

6-959 

•002967 

527630 

1287 

338 

114,244 

38,614,472  18-385 

6-966 

•002959 

528917 

1283 

339 

114,921 

38,958,219 

18-412 

6-973 

•002950 

530200 

1279 

340 

115,600 

39.304,000 

18-439 

6-979 

•002941 

531479 

1275 

341 

116,281 

39,651,821  18-466 

6-986 

•002933 

532754 

1272 

342 

116,964 

40,001,688 

18-493 

6-993 

•002924 

534026 

1268 

343 

117.649 

40,353,607 

18-520 

7-000 

•002915 

535294 

1264 

344 

118,336 

40,707,584 

18-547 

7-007 

•002907 

536558 

1261 

GENERAL    MATHEMATICAL   TABLES. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

345 

119,025 

41,063,625 

18-574 

7-014 

•002899 

537819 

1257 

346 

119,716 

41,421,736 

18-601 

7-020 

•002890 

539076 

1253 

347 

120,409 

41,781,923 

18-628 

7-027 

•002882 

540329 

1250 

348 

121,104 

42.144,192 

18-655 

7-034 

•002874 

541579 

1246 

349 

121,801 

42,508,549 

18-681 

7-040 

•002865 

542825 

1243 

350 

122,500 

42.875,000 

18-708 

7-047 

•002857 

544068 

1239 

351 

123,201 

43,243.551 

18-735 

7-054 

•002849 

545307 

1236 

352 

123,904 

43,614,208 

18-762 

7-061 

•002841 

546543 

1232 

353 

124,609 

43,986,977 

18-788 

7-067 

•002833 

547775 

1228 

354 

125,31(5 

44,361.864 

18-815 

7-074 

•002825 

549003 

1225 

355 

126,025 

44,738,875 

18-842 

7-081 

•002817 

550228 

1222 

356 

126,736 

45,118,016 

18-868 

7-087 

•002809 

551450 

1218 

357  !  127,449 

45,499,293 

18-894 

7-094 

•002801 

552668 

1215 

358  !  128,164 

45,882,712 

18-921 

7-101 

•002793 

553883 

1211 

359 

128,881 

46,268,279 

18-947 

7-107 

•002786 

555094 

1209 

360 

129,600 

46,656,000 

18-974 

7-114 

•002778 

556303 

1204 

361 

130,321 

47,045,881 

19-000 

7-120 

•002770 

557507 

1201 

362 

131,044 

47,437,928 

19-026 

7-127 

•002762 

558709 

1198 

363 

131,769 

47,832,147 

19-052 

7-133 

•002755 

559907 

1195 

364 

132.496 

48,228,544 

19-079 

7-140 

•002747 

561101 

1192 

365 

133,225 

48,627,125 

19-105 

7-146 

•002740 

562293 

1188 

366 

133,956 

49,027,896 

19-131 

7-153 

•002732 

563481 

1185 

367 

134,689 

49,430,863 

19-157 

7-159 

•002725 

564666 

1182 

368 

135,424 

49,836,032 

19-183 

7-166 

•002717 

565848 

1178 

369 

136,161 

50,243,409 

19-209 

7-172 

•002710 

567026 

1175 

370 

136,900 

50,653,000 

19-235 

7-179 

•002703 

568202 

1172 

371 

137,641 

51,064,811 

19-261 

7-185 

•002695 

569374 

1169 

372 

138,384 

51,478,848 

19-287 

7-192 

•002688 

570543 

1166 

373 

139,129 

51,895,117 

19-313 

7-198 

•002681 

571709 

1163 

374 

139,876 

52,313,624 

19-339 

7-205 

•002674 

572872 

1159 

375 

140,625 

52,734,375 

19-365 

7-211 

•002667 

574031 

1157 

376 

141,376 

53,157,376 

19-391 

7-218 

•002660 

575188 

1154 

377 

142.129 

53,582,633 

19-416 

7-224 

•002653 

576341 

1151 

378 

142,884 

54,010,152 

19-442 

7-230 

•002646 

577492 

1148 

379 

143,641 

54,439,939 

19-468 

7-237 

•002639 

578639 

1145 

380 

144,400 

54.872,000 

19-493 

7-243 

•002632 

579784 

1141 

381 

145,161 

55,306,341 

19-519 

7-249 

•002625 

580925 

1138 

382 

145,924 

55,742,968 

19-545 

7-256 

•002618 

582063 

1135 

383 

146,689 

56,181,887 

19-570 

7-262 

•002611 

583199 

1132 

384 

147,456 

56,623,104 

19-596 

7-268  !  -002604 

584331 

1129 

385 

148,225 

57,066,625 

19-621 

7-275  :  -002597 

585461 

1126 

386 

148,996 

57,512,456 

19-647 

7-281  -002591 

586587 

1124 

387 

149,769 

57,960,603 

19-672 

7-287  -002584 

587711 

1121 

388 

150,544 

58,411,072 

19-698  7-294  -002577 

588832 

1118 

389 

151,321 

58,863,869 

19-723  !  7-299  -002571 

589950 

1115 

10 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

390 

152,100 

59,319,000 

19-748 

7-306 

•002564 

591065 

1112 

391 

152,881 

59,776,471 

19-774 

7-312 

•002558 

592177 

1109 

392 

153,064 

60,236,288 

19-799 

7-319 

•002551 

593286 

1106 

393 

154,449 

60,698,457 

19-824 

7-325 

•002545 

594393 

1103 

394 

155,236 

61,162,984 

19-849 

7-331 

•002538 

595496 

1101 

395 

156,025 

61,629,875 

19-875 

7-337 

•002532 

596597 

1098 

396 

156,816 

62,099,136 

19-899 

7-343 

•002525 

597695 

1095 

397 

157,609 

62,570,773 

19-925 

7-349 

•002519 

598791 

1092 

398 

158,404 

63,044,792 

19-949 

7-356 

•002513 

599883 

1090 

399 

159,201 

63,521,199 

19-975 

7-362 

•002506 

600973 

1087 

400 

160,000 

64,000,000 

20-000 

7-368 

•002500 

602060 

10S4 

401 

160,801 

64,481,201 

20-025 

7-374 

•002494 

603144 

1082 

402 

161,604 

64,964,808 

20-049 

7-380 

•002488 

604226 

1079 

403 

162,409 

65,450,827 

20-075 

7-386 

•002481 

605305 

1076 

404 

163,216 

65,939,264 

20-099 

7-392 

•002475 

606381 

1074 

405 

164,025 

66,430.125 

20-125 

7-399 

•002469 

607455 

1071 

406 

164,836 

66,923^16 

20-149 

7-405 

•002463 

608526 

1068 

407 

165,649 

67,419.143 

20-174 

7-411 

•002457 

609594 

1066 

408 

166,464 

67,911,312 

20-199 

7-417 

•002451 

610660 

1063 

409 

167,281 

68,417,929 

20-224 

7-422 

•002445 

611723 

1061 

410 

168,100 

68,921,000 

20-248 

7-429 

•002439 

612784 

1058 

411 

168,921 

69,426,531 

20-273 

7-434 

•002433 

613842 

1055 

412 

169,744 

69,934,528 

20-298 

7-441 

•002427 

614897 

1053 

413 

170,569 

70,444,997 

20-322 

7-447 

•002421 

615950 

1050 

414 

171,396 

70,957,944 

20-347 

7-453 

•002415 

617000 

1048 

415 

172,225 

71,473,375 

20-371 

7-459 

•002410 

618048 

1045 

416 

173,056 

71,991,296 

20-396 

7-465 

•002407 

619093 

1043 

417 

173.889 

72,511,713 

20-421 

7-471 

•002398 

620136 

1040 

418 

174^724 

73,034,632 

20-445 

7-477 

•002392 

621176 

1038 

419 

175.561 

73,560,059 

20-469 

7-483 

•002387 

622214 

1035 

420 

176,400 

74,088,000 

20'494 

7-489 

•002381 

623249 

1033 

421 

177,241 

74,618,461 

20-518 

7-495 

•002375 

624282 

1030 

422 

178,084 

75,151,448 

20-543 

7-501 

•002370 

625312 

1028 

423 

178,929 

75,686,967 

20-567 

7-507 

•002364 

62G340 

1026 

424 

179,776 

76.225.024 

20-591 

7-513 

•002358 

627366 

1023 

425 

180,625 

76,765,625 

20-615 

7-518 

•002353 

628389 

1021 

426 

181,476 

77,308,776 

20-639 

7-524 

•002347 

629410 

1018 

427 

182,329 

77,854.483 

20-664 

7-530 

•002342 

630428 

1016 

428 

183,184 

78,402,752 

20-688 

7-536 

•002336 

631444 

1013 

429 

184,041 

78,953,589 

20-712 

7-542 

•002331 

632457 

1011 

430 

184,900 

79,507,000 

20-736 

7-548 

•002326 

633468 

1009 

431 

185,761 

80,062,991 

20-760 

7-:>r,4  -002320 

634477 

1007 

432 

186,624 

80,621,568 

20-785  :  7-559  '  -002315 

635484 

1004 

433 

187,489 

81,182,737 

20-809  7-565  -002309 

636488 

1002 

434 

188,356 

81,746,504 

20-833  7-571  -002304 

637490 

999 

GENERAL    MATHEMATICAL   TABLES. 


11 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

435 

189,225 

82,312,875 

20-857 

7*577 

•002299 

638489 

997 

436 

190,096 

82,881,856 

20-881 

7-583 

•002294 

639486 

995 

437 

H>0,lh59 

83,453,453 

20-904 

7-588 

•002288 

640481 

993 

438 

191,844 

84,027.  (572 

20-928 

7-594 

•002283 

641474 

991 

439 

192,721 

84,604,519 

20-952 

7-600 

•002278 

642465 

988 

440 

193,600 

85,184,000 

20-976 

7-606 

•002273 

643453 

986 

441 

194,481 

85,76(5.121 

21-000 

7-612 

•002268 

644439 

983 

442 

195,364 

8(>,3r>o,3SS 

21-024 

7-617 

•002262 

645422 

981 

443 

196,249 

86,938,307 

21-047 

7-623 

•002257 

646404 

979 

444 

197,136 

87,528,384 

21-071 

7-629 

•002252 

647383 

977 

445 

198,025 

88,121,125 

21-095 

7-635 

•002247 

648360 

975 

446 

198,916 

88,71(5.  53(5 

21-119 

7-640 

•002242 

649335 

973 

447 

199,809 

89,314,623 

21-142 

7-646 

•002237 

650308 

970 

448 

200,704 

89,915,392 

21-166 

7-652 

•002232 

651278 

968 

449 

201,601 

90,518,849 

21-189 

7-657 

•002227 

652246 

967 

450 

202,500 

91,125,000 

21-213 

7-663 

•002222 

653213 

964 

451 

203,401 

91,733,851 

21-237 

7-669 

•002217 

654177 

962 

452 

204,304 

92,345,408 

21-260 

7-674 

•002212 

655138 

960 

453 

205,209 

92,959,677 

21-284 

7-680 

•002208 

656098 

958 

454 

206,106 

93,576,664 

21-307 

7-686 

•002203 

657056 

956 

455 

207,025 

94,196.375 

21-331 

7-691 

•002198 

658011 

954 

456 

207.936 

94,818,816 

21-354 

7-697 

•002193 

658965 

951 

157 

208,849 

95,443^993 

21-377 

7-703 

•002188 

659916 

949 

458 

209,764 

96,071,912 

21-401 

7-708 

•002183 

660865 

947 

159 

210,681 

96,702,579 

21-424 

7-714 

•002179 

661813 

945 

460 

211,600 

97,336.000 

21-447 

7-719 

•002174 

662758 

943 

461 

212,521 

97,972,181 

21-471 

7-725 

•002169 

663701 

941 

462 

213,444 

98,611,128 

21-494 

7-731 

•002165 

664642 

939 

463 

214,3(59 

99,252,847 

21-517 

7-736 

•002160 

665581 

937 

464 

215,296 

99,897,345 

21-541 

7-742 

•002155 

666518 

935 

465 

216.225 

100,544,625 

21-564 

7-747 

•002151 

667453 

933 

466 

217,156 

101,194,696 

21-587 

7-753 

•002146 

668386 

931 

467 

218,089 

101,847.563 

21-610 

7-758 

•002141 

669317 

92!) 

468 

219,024 

102,503,232 

21-633 

7-764 

•002137 

670246 

927 

469 

219,961 

103,161,709 

21-656 

7-769 

•002132 

671173 

025 

470 

220,900 

103,823,000 

21-679 

7-775 

•002128 

672098 

923 

471 

221,841 

104,487,111 

21-702 

7-780 

•002123 

673021 

921 

472 

222,784 

105.154,048 

21-725 

7-786 

•002119 

673942 

919 

473 

223,729 

105^823,817 

21-749 

7-791 

•002114 

674861 

917 

474 

224,676 

106,496,424 

21-771 

7-797 

•002110 

675778 

915 

475 

225,625 

107,171,875 

21-794 

7-802 

•002105 

676694 

913 

476 

226,576 

107,850,176 

21-817 

7-808 

•002101 

677607 

911 

477 

227,529 

108,531,333 

21-840 

7-813 

•002096 

678518 

910 

478 

228,484 

109,215,352 

21-863 

7-819 

•002092 

679428 

908 

479 

229,441 

109,902,239 

21-886 

7-824 

•002088 

680336 

905 

12 


GAS    ENGINEERS    POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

480 

230,400 

110,592,000 

21-909 

7-830 

•002083 

681241 

904 

481 

231,361 

111,284,641 

21-932 

7-835 

•002079 

682145 

902 

482 

232,324 

111,980,168 

21-954 

7-840 

•002075 

683047 

900 

483 

233,289 

112,678,587 

21-977 

7-846 

•002070 

683947 

898 

484 

234,256 

113,379,904 

22-000 

7-851 

•002066 

684845 

89(5 

485 

235,225 

114,084,125 

22-023 

7-857 

•002062 

685742 

894 

486 

236,196 

114,791,256 

22-045 

7-862 

•002058 

686636 

893 

487 

237,169 

115,501,303 

22-069 

7-868 

•002053 

687529 

891 

488 

238,144 

116,214,272 

22-091 

7-873 

•002049 

688420 

889 

489 

239,121 

116,936,169 

22-113 

7-878 

•002045 

689309 

887 

490 

240,100 

117,649,000 

22-136 

7-884 

•002041 

690196 

885 

491 

241,081 

118,370,771 

22-158 

7-889 

•002037 

691081 

884 

492 

242,064 

119,095,488 

22-181 

7-894 

•002033 

691965 

882 

493 

243,049 

119,823,157 

22-204 

7-899 

•002028 

692847 

880 

494 

244,036 

120,553,784 

22-226 

7-905 

•002024 

693727 

878 

495 

245,025 

121,287,375 

22-248 

7-910 

•002020 

694605 

876 

496 

246,016 

122,023,936 

22-271 

7-915 

•002016 

695482 

874 

497 

247,009 

122,763,473 

22-293 

7-921 

•002012 

696356 

873 

498 

248,004 

123,505,992 

22-316 

7-926 

•002008 

697229 

871 

499 

249,001 

124,251,499 

22-338 

7-932 

•002004 

698101 

869 

500 

250,000 

125,000,000 

22-361 

7-937 

•002000 

698970 

868 

501 

251,001 

125,751,501 

22-383 

7-942 

•001996 

699838 

866 

502 

252,004 

126,506,008 

22-405 

7-947 

•001992 

700704 

864 

503 

253,009 

127,263,527 

22-428 

7-953 

•001988 

701568 

862 

504 

254,016 

128,024,864 

22-449 

7-958 

•001984 

702431 

860 

505 

255,025 

128,787,625 

22-472 

7-963 

•001980 

703291 

859 

506 

256,036 

129,554,216 

22-494 

7-969 

•001976 

704151 

857 

507 

257,049 

130,323,843 

22-517 

7-974 

•001972 

705008 

856 

508 

258,064 

131,096,512 

22-539 

7-979 

•001969 

705864 

854 

509 

259,081 

131,872,229 

22-561 

7-984 

•001965 

706718 

852 

510 

260,100 

132,651,000 

22-583 

7-989 

•001961 

707570 

851 

511 

261,121 

133,432,831 

22-605 

7-995 

•001957 

708421 

849 

512 

262,144 

134,217,728 

22-627 

8-000 

•001953 

709270 

847 

513 

263,169 

135,005,697 

22-649 

8-005 

•001949 

710117 

846 

514 

264,196 

135,796,744 

22-671 

8-010 

•001946 

710963 

844 

515 

265,225 

136,590,875 

22-694 

8-016 

•001942 

711807 

843 

516 

266,256 

137,388,096 

22-716 

8-021 

•001938 

712650 

841 

517 

267,289 

138,188,413 

22-738 

8-026 

•001934 

713491 

839 

518 

268,324 

138,991,832 

22-759 

8-031 

•001931 

714330 

837 

519 

269,361 

139,798,359 

22-782 

8-036 

•001927 

715167 

836 

520 

270,400 

140,608,000 

22-803 

8-041 

•001923 

716003 

835 

521 

271,441 

141,420,761 

22-825 

8-047 

•001919 

716838 

833 

522 

272,484 

142,236,648 

22-847 

8-052 

•001916 

717671 

831 

523 

273,529 

143,055,667 

22-869 

8-057 

•001912 

718502 

829 

524 

274,576 

143,877,824 

22-891 

8-062 

•001908 

719331 

828 

GENERAL   MATHEMATICAL   TABLES. 


13 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

525 

275,625 

144,703,125 

22-913 

8-067 

•001905 

720159 

827 

526 

276,676 

145,531,576 

22-935 

8-072 

•001901 

720986 

825 

527 

277,729 

146,363,183 

22-956 

8-077 

•001898 

721811 

823 

528 

278.784 

147,197,952 

22-978 

8-082 

•001894 

722634 

822 

529 

279,841 

148,035,889 

23-000 

8-087 

•001890 

723456 

820 

530 

280.900 

148,877,000 

23-022 

8-093 

•001887 

724276 

819 

531 

281,961 

149,721,291 

23-043 

8-098 

•001883 

725095 

817 

532 

283,024 

150,568,768 

23-065 

8-103 

•001880 

725912 

815 

533 

284,089 

151,419,437 

23-087 

8-108 

•001876 

726727 

814 

534 

285,156 

152,273,304 

23-108 

8-113 

•001873 

727541 

813 

535 

286,225 

153,130,375 

23-130 

8-118 

•001869 

728354 

811 

536 

287,296 

153,990,656 

23-152 

8-123 

•001866 

729165 

809 

537 

288,369 

154,854,153 

23-173 

8-128 

•001862 

729974 

808 

538 

289,444 

155,720,872 

23-195 

8-133 

•001859 

730782 

807 

539 

290,521 

156,590,819 

23-216 

8-138 

•001855 

731589 

805 

540 

291,600 

157,464,000 

23-238 

8-143 

•001852 

732394 

803 

541 

292,681 

158,340,421 

23-259 

8-148 

•001848 

733197 

802 

542 

293.764 

159.220,088 

23-281 

8-153 

•001845 

733999 

801 

543 

294,849 

160,103,007 

23-302 

8-158 

•001842 

734800 

799 

544 

295,936 

160,989,184 

23-324 

8-163 

•001838 

735599 

798 

545 

297,025 

161,878,625 

23-345 

8-168 

•001835 

736397 

796 

546 

298,116 

162,771,336 

23-367 

8-173 

•001832 

737193 

794 

547 

299,209 

163,667,323 

23-388 

8-178 

•001828 

737987 

793 

548 

300,304 

164,566,592 

23-409 

8-183 

•001825 

738781 

792 

549 

301,401 

165,469,149 

23-431 

8-188 

•001821 

739572 

791 

550 

302,500 

166,375,000 

23-452 

8-193 

•001818 

740363 

789 

551 

3U3,601 

167,281,151 

23-473 

8-198 

•001815 

741152 

787 

552 

304,704 

168,196,608 

23-495 

8-203 

•001812 

741939 

786 

553 

305,809 

169,112,377 

23-516 

8-208 

•001808 

742725 

785 

554 

306,916 

170,031,464 

23-537 

8-213 

•001805 

743510 

783 

555 

308,025 

170,953,875 

23-558 

8-218 

•001802 

744293 

782 

556 

309,136 

171,879,616 

23-579 

8-223 

•001799 

745075 

780 

557 

310,249 

172,808,693 

23-601 

8-228 

•001795 

745855 

779 

558 

311,364 

173,741,112 

23-622 

8  233 

•001792 

746634 

778 

559 

312,481 

174,676,879 

23-643 

8-238 

•001789 

747412 

776 

560 

313,600 

175,616,000 

23-664 

8-242 

•001786 

748188 

775 

561 

314,721 

176,558,481 

23-685 

8-247 

•001783 

748963 

773 

562 

315,844 

177,504,328  23-706 

8-252 

•001779 

749736 

772 

563 

316,969 

178,453,547  23-728 

8-257 

•001776 

750508 

771 

564 

318,096 

179,406,144  23-749 

8-262 

•001773 

751279 

769 

565 

319,225 

180,362,125  23-769 

8-267 

•001770 

752048 

768 

566 

320,356 

181,321,496  23  791 

8'272 

•001767 

752816 

767 

567 

321,489 

182,284,263  23-812 

8-277 

•001764 

753583 

765 

568 

322,624 

183,250,432  23'833 

8-282 

•001761 

754348 

764 

569 

323,761 

184,220,009  23-854 

8-286 

•001757 

755112 

763 

14 


GAS    ENGINEER  S   POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

570 

324,900 

185,193,000 

23-875 

8-291 

•001754 

755875 

761 

571 

326,041 

186,169,411 

23-896 

8°296 

•001751 

756636 

7GO 

572 

327,184 

187,149,248 

23-916 

8-301 

•001748 

757396 

759 

573 

328,329 

188.132,517 

23-937 

8-306 

•001745 

758153 

757 

574 

329,476 

189,119,224 

23-958 

8-311 

•001742 

758912 

756 

575 

330,625 

190,109,375 

23-979 

8-315 

•001739 

759668 

754 

576 

331,776 

191.102,976 

24-000 

8-320 

•001736 

760422 

753 

577 

332,929 

192,100,033 

24-021 

8-325 

•001733 

761176 

752 

578 

334,084 

193,100,552 

24-042 

8-330 

•001730 

761928 

751 

579 

335,241 

194,104,539 

24-062 

8-335 

•001727 

762679 

749 

580 

336,400 

195,112,000 

24-083 

8-339 

•001724 

763228 

748 

581 

337,561 

196,122,941 

24-104 

8-344 

•001721 

764176 

747 

582 

338,724 

197,137,368 

24-125 

8-349 

•001718 

764923 

74(5 

583 

339,889 

198,155,287 

24-145 

S-354 

•001715 

765669 

744 

584 

341,056 

199,176,704 

24-166 

8-359 

•001712 

766413 

743 

585 

342,225 

200,201,625 

24-187 

8-363 

•001709 

767156 

742 

586 

343,396 

201,230,056 

24-207 

8-368 

•001706 

767898 

740 

587 

344,569 

202,262,003 

24-228 

8-373 

•001704 

768638 

739 

588 

345,744 

203,297,472 

24-249 

8-378 

•001701 

769377 

738 

589 

346,921 

204,336,469 

24-269 

8-382 

•001698 

770115 

737 

590 

348,100 

205.379,000 

24-289 

8-387 

•001695 

770852 

735 

591 

349,281 

206,425,071 

24-310 

8-392 

•001692 

771587 

734 

592 

350,464 

207,474,688 

24-331 

8-397 

•001689 

772322 

733 

593 

351,649 

208,527,857 

24-351 

8-401 

•001686 

773055 

731 

594 

352,836 

209,584,584 

24-372 

8-406 

•001684 

773786 

730 

595 

354,025 

210,644,875 

24-393 

8-411 

•001681 

774517 

729 

596 

355,216 

211,708,736 

24-413 

8-415 

•001678 

775246 

728 

597 

356,409 

212,776,173 

24-433 

8-420 

•001675 

775974 

727 

598 

357,604 

213,847,192 

24-454 

8-425 

•001672 

776701 

726 

599 

358,801 

214,921,799 

24-474 

8-429 

•001669 

777427 

724 

600 

360.000 

216,000,000 

24-495 

8-434 

•001667 

778151 

723 

601 

361,201 

217,081,801 

24-.-)  15 

8-439 

•001664 

778874 

722 

602 

362,404 

218,167,208 

24-536 

8-444 

•001661 

779596 

721 

603 

363,609 

219,256,227 

24-556 

8-448 

•001658 

780317 

720 

604 

364,816 

220,348,864 

24-576 

8-453 

•001656 

781037 

719 

605 

366,025 

221,445,125 

24-597 

8-458 

•001653 

781755 

718 

606 

367,236 

222,545,016 

24-617 

8-462 

•001650 

782473 

716 

607 

368,449 

223,648,543 

24-637 

8-467 

•001647 

783189 

715 

608 

369,664 

224,755,712 

24-658 

8-472 

•001645 

783904 

714 

609 

370,881 

225.866,529 

24-678 

8-476 

•001642 

784617 

713 

610 

372,100 

226,981,000 

24-698 

8-481 

•001639 

785330 

711 

611 

373,321 

228,099,131 

24-718 

8-485 

•001637 

786041  ,710 

612 

374,544 

229,220,928 

24-739 

8-490 

•001634 

786751 

709 

613 

375,769 

230,346,397 

24-758 

8-495 

•001631 

787460 

708 

614  376,996 

231,475,544 

24-779 

8-499 

•001629 

788168 

707 

GENERAL    MATHEMATICAL    TABLES. 


15 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

615  378,225 

232,608,375 

24-799  8-504 

•001626 

788875 

706 

616  379,456 

233,744,896 

24-819  8-509 

•001623 

789581 

704 

617  380,689 

234,885,113 

24-839 

8-513 

•001621 

790285 

703  ' 

618 

381,924 

236.029,032 

24-859 

8-518 

•001618 

790988 

702 

619 

383,161 

237,176,659 

24-879 

8-522 

•001616 

791691 

701 

620 

384,400 

238,628,000 

24-899 

8-527 

•001613 

792392 

700 

621 

385,641 

239,483,061 

24-919 

8-532 

•001610 

793092 

699 

622  386,884 

240,641,348 

24-939 

8-536 

•001608 

793790 

698 

623  388.129 

241,804,367 

24-959  !  8-541 

•001605 

794488 

697 

624  389^376 

242,970,624 

24-980  8-545 

•001603 

795185 

695 

625 

390,625 

244,140,625 

25-000  1  8-549 

•001600 

795880 

694 

626  391,876 

245.314,376 

25-019  8-554 

•001597 

796574 

693 

627  393,129 

246,491,883 

25-040 

8-559 

•001595 

797268 

692 

628  ;  394,384 

247,673,152 

25-059  8-563 

•001592 

797960 

691 

629  395,641 

248,858,189 

25-079 

8-568 

•001590 

798651 

690 

630  396,900 

250,047,000 

25-099 

8-573 

•001587 

799341 

689 

631  398,161 

251,239,591 

25-119 

8-577 

•001585 

800029 

688 

632  399,424 

252,435,968 

25-139 

8-582 

•001582 

800717 

687 

633  400,689 

253,636,137 

25-159 

8-586 

•001580 

801404 

685 

634  401,956 

254,840,104 

25-179 

8-591 

•001577 

802089 

684 

635  403,225 

256.047,875 

25-199 

8-595 

•001575 

802774 

683 

636  404,496 

257,259,456 

25-219 

8-599 

•001572 

803457 

682 

637  405,769 

258.474,853 

25-239 

8-604 

•001570 

804139 

681 

638  407,044 

259,694,072 

25-259 

8-609 

•001567 

804821 

680 

639  408,321 

260,917,119 

25-278 

8-613 

•001565 

805501 

679 

640 

409,600 

262,114,COO 

25-298 

8-618 

•001563 

806180 

678 

641  410,881 

263,374.721 

2V318 

8-622 

•001560 

806858 

677 

642  412.164 

264,609,2«8 

25-338 

8-627 

•001558 

807535 

676 

643  '  413,449 

265,847,707 

25-357 

8-631 

•001555 

808211 

675 

644  414,736   267,089,984 

25-377 

8-636 

•001553 

808886 

674 

645  j  416,025  |  268,836,125 

25-397 

8-640 

•001550 

809560 

673 

646  !  417,316  j  269,586,136 

25-416 

8-644 

•001548 

810233 

672 

647  i  418,609  270,840,023 

25-436 

8-649 

•001546 

810904 

671 

648  i  419,904 

272,097,792 

25-456 

8-653 

•001543 

811575 

670 

649 

421,201 

273,359,449 

25-475 

8-658 

•001541 

812245 

669 

650 

422,500 

274,625,000 

25-495 

8-662 

•001538 

812913 

668 

651 

423,801 

275,894,451 

25*515 

8-667 

•001536 

813581 

667 

652 

425,104 

277,167,808 

25-534 

8-671 

•001534 

814248 

666 

653 

426,409 

278,445,077 

25-554 

8-676 

•001531 

814913 

665 

654 

427,716 

279,726.264 

25-573 

8-680 

•001529 

815578 

664 

655 

429,025 

281,0  1U75 

25-593 

8-684 

•001527 

816241 

663 

656 

430,336 

282,800,416 

25-612 

8-689 

•001524 

816904 

662 

657 

431,649 

283,593,393 

25-632 

8-693 

•001522 

817565 

661 

658 

432,964 

284,890,312 

25-651 

8-698 

•001520 

818226 

660 

659 

434.281 

286,191,179 

25-671 

8-702 

•001517 

818885 

659 

16 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

660 

435,600 

287,496,000 

25-690 

8-706 

•001515 

819544 

658 

661 

436,921 

288,804.781 

25-710 

8-711 

•001513 

820201 

657 

662 

438,244 

290,117,528 

25-720 

8-715 

•001511 

820858 

656 

663 

439,569 

291,434,247 

25-749 

8-719 

•001508 

821514 

654 

664 

440,896 

292,754,1)44 

25*768 

8-724 

•001506 

822168 

653 

665 

442,225 

294,079,625 

25-787 

8-728 

•001504 

822822 

652 

666 

443,556 

295,408,296 

25-807 

8-733 

•001502 

823474 

651 

667 

444,889 

296,740,963 

25-826 

8-737 

•001499 

824126 

650 

668 

446,224 

298,077,632 

25-846 

8-742 

•001497 

824776 

650 

669 

447,561 

299,418,309 

25-865 

8-746 

•001495 

825426 

649 

670 

448,900 

300,763,000 

25-884 

8-750 

•001493 

826075 

648 

671 

450,241 

302,111,711 

25-904 

8-753 

•001490 

826723 

647 

672 

451,584 

303,464,448 

25-923 

8-759 

•001488 

827369 

646 

673 

452,929 

304,821,217 

25-942 

8-763 

•001486 

828015 

645 

674 

454,276 

306,182,024 

25-961 

8-768 

•001484 

828660 

644 

675 

455,625 

307,546,875 

25-981 

8-772 

•001481 

829304 

643 

676 

456.976 

308,915,776 

26-000 

8-776 

•001479 

829947 

642 

677 

458,329 

310,288,733 

26-019 

8-781 

•001477 

830589 

641 

678 

459,684 

311,665,752 

26-038 

8-785 

•001475 

831230 

640 

679 

461,041 

313,046,839 

26-058 

8-789 

•001473 

831870 

639 

680 

462,400 

314,432,000 

26-077 

8-794 

•001471 

832509 

638 

681 

463,761 

315,821,241 

26-096 

8'798 

•001468 

833147 

637 

682 

465,124 

317,214,568 

26-115 

8-802 

•001466 

833784 

637 

683 

466,489 

318,611,987 

26-134 

8-807 

•001464 

834421 

636 

684 

467,856 

320,013,504 

26-153 

8-811 

•001462 

835056 

635 

685 

469,225 

321,419,125 

26-172 

8-815 

•001460 

835691 

634 

686 

470,596 

322,828,856 

26-192 

8-819 

•001458 

836324 

633 

687 

471,969 

324,242,703 

26-211 

8-824 

•001456 

836957 

632 

688 

473,344 

325,660,672 

26-229 

8-8:J8 

•001453 

837588 

631 

689 

474,721 

327,082,769 

26-249 

8-832 

•001451 

838219 

630 

690 

476,100 

328,509,000 

26-268 

8-836 

•001449 

838849 

629 

691 

477,481 

329,939,371 

26-287 

8-841 

•001447 

839478 

628 

692 

478,864 

331,373,888 

26-306 

8-845 

•001445 

840106 

627 

693 

480,249 

332,812,557 

26-325 

8-849 

•001443 

840733 

626 

694 

481,636 

334,255,384 

26-344 

8-853 

•001441 

841359 

625 

695 

483,025 

335,702,375 

26-363 

8-858 

•001439 

841985 

624 

696 

484,416 

337,153,536 

26-382 

8-862 

•001437 

842609 

623 

697 

485,809 

338,608,873 

26-401 

8-866 

•001435 

843233 

622 

698 

487,204 

340,068,392 

26-419 

8-870 

•001433 

843855 

622 

699 

488,601 

341,532,099 

26-439 

8-875 

•001431 

844477 

621 

700 

490,000 

343,000,000 

26-457 

8-879 

•001429 

845098 

620 

701 

491.401 

344,472,101 

26-476 

8-883 

•001427 

845718 

619 

702 

492^04 

345,948,088 

26-495 

8-887 

•001425 

846337 

618 

703 

494,209 

347,528,927 

26-514 

8-892 

•001422 

846955 

617 

704 

495,616 

348,913,664 

26-533 

8-896 

•001420 

847573 

616 

GENERAL    MATHEMATICAL    TABLES. 


17 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

705 

497,025 

350,402,625 

26-552 

8-900 

•001418 

848189 

615 

706 

498,430 

351,895,816 

26-571 

8-904 

•001416 

848805 

614 

707 

499,849 

353,393,243 

26-589 

8-908 

•001414 

849419 

614 

708 

501,264 

354,894,912 

26-608 

8-913 

•001412 

850033 

613 

709 

502,681 

356,400,829 

26-627 

8-917 

•001410 

850646 

612 

710 

504,100 

357,911,000 

26-644 

8-921 

•001408 

851258 

611 

711 

505,521 

359,425,431 

26-664 

8-925 

•001406 

851870 

610 

712 

506,944 

360,944.128 

26-683 

8-929 

•001404 

852480 

610 

713 

508,369 

362,467,097 

26-702 

8-934 

•001403 

853090 

609 

714 

509.796 

363,994.344 

26-721 

8-938 

•001401 

853698 

608 

715 

511,225 

365,525.875 

26-739 

8-942 

•001399 

854306 

607 

716 

512,656 

367,061,696 

26-758 

8-946 

•001397 

854913 

606 

717 

514,089 

368,601,813 

26-777 

8-950 

•001395 

855519 

605 

718 

515,524 

370.146.232 

26-795 

8-954 

•001393 

856124 

604 

719 

516,961 

371^694,959 

26-814 

8-959 

•001391 

856729 

603 

720 

518,400 

373,248,000 

26-833 

8-963 

•001389 

857332 

603 

721  519.841 

374,805,361 

26-851 

8-967 

•001387 

857935 

602 

722 

521,284 

376,367,048 

26-870 

8-971 

•001385 

858537 

601 

723 

522,729 

377,933,007 

26-889 

8-975 

•001383 

859138 

600 

724 

524,176 

379,503,424 

26-907 

8-979 

•001381 

859739 

599 

725 

525.625 

381,078,125 

26-926 

8-983 

•001379 

860338 

598 

726 

527,076 

382,657,176 

26-944 

8-988 

•001377 

860937 

597 

727 

528,529 

384,240,583 

26-963 

8-992 

•001376 

861534 

597 

728 

529,984 

385,828,352 

26-991 

8-996 

•001374 

862131 

596 

729 

531,441 

387,420,489 

27-000 

9-000 

•001372 

862728 

595 

730 

532,900 

389,017,000 

27-018 

9-004 

•001370 

863323 

594 

731 

534,361 

390,617,891 

27-037 

9-008 

•001368 

863917 

594 

732 

535,824 

392,223,168 

27-055  9-012 

•001366 

864511 

593 

733 

537,289 

393,832,837 

27-074  9-016 

•001364 

865104 

592 

734 

538,756 

395,446,904 

27-092  9-020 

•001362 

865696 

591 

735 

540,225 

397,065,375 

27-111 

9-023 

•001361 

866287 

590 

736 

541,696 

398,688,256 

27-129 

9-029 

•001359 

866878 

589 

737 

543,169 

400,315,553 

27-148 

9-033 

•001357 

867467 

589 

738 

544,644 

401,947,272 

27-166 

9-037 

•001355 

868056 

588 

739 

546,121 

403,583,419 

27-184 

9-041 

•001353 

868644 

587 

740 

547,600 

405,224,000 

27-203 

9-045 

•001351 

869232 

586 

741 

549,081 

406,869,021 

27-221 

9-049 

•001350 

869818 

586 

742 

550,564 

408,518,488 

27-239 

9-053 

•001348 

870404 

585 

743 

552,049 

410,172,407 

27-258 

9-057 

•001346 

,870989 

584 

744 

553,536 

411,830,784 

27-276 

9-061 

•001344 

871573 

583 

745 

555,025  j  413,493,625 

27-295 

9-065 

•001342 

872156 

583 

746 

556,516 

415.160.936 

27-313 

9-069 

•001340 

872739 

582 

747 

558,009 

416,832,723 

27-331 

9-073 

•001339 

873321 

581 

748 

559,504 

418,508,992 

27-349 

9-077 

•001337 

873902 

580 

749  |:>ei,ooi 

420,189,749 

27-368  !  9-081 

•001335 

874482 

579 

G.E. 


18 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

750 

562,500 

421,875,000 

27-386 

9-086 

•001333 

875061 

579 

751 

564,001 

423,564,751 

27-404 

9-089 

•001332 

875640 

578 

752 

565,504 

424,525,900 

27-423 

9-094 

•001330 

876218 

577 

753 

567,009 

426,957,777 

27-441 

9-098 

•001328 

876795 

576 

754 

568,516 

428,661,064 

27-459 

9-102 

•001326 

877371 

576 

755 

570,025 

430,368,875 

27-477 

9-106 

•001325 

877947 

575 

756 

571,536 

432,081,216 

27-495 

9-109 

•001323 

878522 

574 

757 

573,049 

433,798,093 

27-514 

9-114 

•001321 

879096 

573 

758 

574,564 

435,519,512 

27-532 

9-118 

•001319 

879669 

573 

759 

576,081 

437,245,479 

27-549 

9-122 

•001318 

880242 

572 

760 

577,600 

438,976,000 

27-568 

9-126 

•001316 

880814 

571 

761 

579,121 

440,711,081 

27-586 

9-129 

•00^314 

881385 

570 

762 

580,644 

442,450,728 

27-604 

9-134 

•001312 

881955 

570 

763 

582,169 

444,194,947 

27-622 

9-138 

•001311 

882525 

569 

764 

583,696 

445,943,744 

27-640 

9-142 

•001309 

883093 

568 

765 

585,225 

447,697,125 

27-659 

9-146 

•001307 

883661 

567 

766 

586,756 

449,455,096 

27-677 

9-149 

•001305 

884229 

566 

767 

588,289 

451,217,663 

27-695 

9-154 

•001304 

884795 

566 

768 

589,824 

452,984,832 

27-713 

9-158 

•001302 

885361 

565 

769 

591,361 

454,756,609 

27-731 

9-162 

•001300 

885926 

565 

770 

592,900 

456.533,000 

27-749 

9-166 

•001299 

886491 

564 

771 

594,441 

458,314,011 

27-767 

9-169 

•001297 

887054 

563 

772 

595,984 

460,099,648 

27-785 

9-173 

•001295 

887617 

562 

773 

597,529 

461,889,917 

27-803 

9-177 

•001294 

888179 

562 

774 

599,076 

463,684,824 

27-821 

9-181 

•001292 

888741 

561 

775 

600,625 

465,484,375 

27-839 

9-185 

•001290 

889302 

560 

776 

602,176 

467,288,576 

27-857 

9-189 

•001289 

889862 

559 

777 

603,729 

469,097,433 

27-875 

9-193 

•001287 

890421 

559 

778 

605,284 

470,910,952 

27-893 

9-197 

•001285 

890980 

558 

779 

606,841 

472,729,139 

27-910 

9-201 

•001284 

891537 

558 

780 

608,400 

474,552,000 

27-928 

9-205 

•001282 

892095 

556 

781 

609,961 

476,379,541 

27-946 

9-209 

•001280 

892651 

556 

782 

611,524 

478,211,768 

27-964 

9-213 

•001279 

893207 

555 

783 

613,089 

480,048,687 

27-982 

9-217 

•001277 

893762 

554 

784 

614,656 

481,890,304 

28-000 

9-221 

•001276 

894316 

554 

785 

616,225 

483,736,625 

28-017 

9-225 

•001274 

894870 

553 

786 

617,796 

485,587,656 

28-036 

9-229 

•001272 

895423 

552 

787 

619,369 

487,443,403 

28-053 

9-233 

•001271 

895975 

551 

788 

620,944 

489,303,872 

28-071 

9-237 

•001269 

896526 

551 

789 

622,521 

491,169,069 

28-089 

9-240 

•001267 

897077 

550 

790 

624,100 

493,039,000 

28-107 

9-244 

•001266 

897627 

549 

791 

625,681 

494,913,671 

28-125 

9-248 

•001264 

898176 

549 

792 

627,624 

496,793,088 

28-142 

9-252 

•001263 

898725 

548 

793 

628,849 

498,677,257 

28-160 

9-256 

•001261 

899273 

547 

794 

630,436 

500,566,184 

28-178 

9-260 

•001259 

899821 

546 

GENERAL    MATHEMATICAL    TABLES. 


19 


No. 

Square. 

~  .      ,  Square 
Cube-      Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

795 

632,025 

502,459,875  28-196 

9-264 

•001258 

900367 

546 

796 

633,616 

504,358,336  28-213 

9-268 

•001256 

900913 

545 

797 

635,209 

506,261,573  28-231 

9-271 

•001255 

901458 

545 

798 

636,804 

508,169,592  28-249 

9-275 

•001253 

902003 

544 

799 

638,401 

510,082,399  28-266 

9-279 

•001251 

902547 

543 

800 

640,000 

512,000,000  28-284 

9-283 

•001250 

903090 

542 

801 

641,601 

513,922,401  28-302 

9-287 

•001248 

903633   541 

802 

643,204 

515,849,608  28-319 

9-291 

•001247 

904174   541 

803 

644,809 

517,781,627 

28-337 

9-295 

•001245 

904716 

540 

804 

646,416 

519,718,464  28'355 

9-299 

•001244 

905256 

540 

805 

648,025 

521,660,125  28-372 

9-302 

•001242 

905796  539 

806 

649,636 

523,606,616 

28-390 

9-306 

•001241 

906335   538 

807 

651,249 

525,557,943 

28-408 

9-310 

•001239 

906874 

537 

808 

652,864 

527,514,112 

28-425 

9-314 

•001238 

907411 

537 

809 

654,481 

529,475,129 

28-443 

9-318 

•001236 

907949 

536 

810 

656,100 

531,441,000 

28-460 

9-321 

•001235 

908485 

536 

811 

657,721 

533,411,731 

28-478 

9-325 

•001233 

909021 

535 

812 

659,344 

535,387,328 

28-496 

9-329 

•001232 

909556 

535 

813 

660,969 

537,366,797 

28-513 

9-333 

•001230 

910091 

534 

814 

662,596 

539,353,144 

28-531 

9-337 

•001229 

910624 

533 

815 

664,225 

541,343,375 

28-548 

9-341 

•001227 

911158 

533 

816 

665,856 

543,338,496 

28-566 

9-345 

•001225 

911690 

533 

817 

667,489 

545,338,513 

28-583 

9-348 

•001224 

912220 

532 

818 

669,124 

547,343,432 

28-601 

9-352 

•001222 

912753 

531 

819 

670,761 

549,353,259 

28-618 

9-356 

•001221 

913284 

530 

820 

672,400 

551,368,000 

28-636 

9-360 

•001220 

913814 

529 

821 

674,041 

553,387,661 

28-653 

9-364 

•001218 

914343 

529 

822 

675,684 

555,412,248 

28-670 

9-367 

•001217 

914872 

528 

823 

677,329 

557,441,767 

28-688 

9-371 

•001215 

915400 

527 

824 

678,976 

559,476,224 

28-705 

9-375 

•001214 

915927 

527 

825 

680,625 

561,515,625 

28-723 

9-379 

•001212 

916454 

526 

826 

682,276 

563,559,976 

28-740 

9-383 

•001211 

916980 

526 

827 

683,929 

565,609,283 

28-758 

9-386 

•001209 

917506 

525 

828 

685,584 

567,663,552 

28-775 

9-390 

•001208 

918030 

524 

829 

687,241 

569,722,789 

28-792 

9-394  -001206 

918555 

523 

830 

688,900 

571,787,000 

28-810 

9-398 

•001205 

919078 

523 

831 

690,561 

573,856,191 

28-827 

9-401 

•001203 

919601 

522 

832 

692,224 

575,930,368 

28-844 

9-405 

•001202 

920123 

522 

833 

693,889 

578,009,537 

28-862 

9-409 

•001200 

920645 

521 

834 

695,556 

580,093,704 

28-879 

9-413 

•001199 

921166 

520 

835 

697.225 

582,182,875 

28-896 

9-417 

•001198 

921686 

520 

836 

698,896 

584,277,056 

28-914 

9-420 

•001196 

922206 

519 

837 

700,569 

586,376,253 

28-931 

9-424 

•001195 

922725 

519 

838 

702,244 

588,480,472 

28-948 

9-428 

•001193 

923244 

518 

839 

703,921 

590,589,719 

28-965 

9-432 

•001192 

923762 

517 

20 


GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square  Cube 
Root.   Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

840  705.600 

592,704,000 

28-983  i  9-435 

•001190 

924279 

517 

841  707.281 

594,823.321 

29-000 

9-439 

•001189 

924796 

516 

842  708,964 

596,947,688 

29-017 

9-443 

•001188 

925312 

516 

843 

710,649 

599,077,107 

29-034 

9-447 

•001186 

1)25828 

515 

844 

712,336 

601,211,584 

29-052 

9-450 

•001185 

D263-J2 

r.ii 

845 

714,025 

603,351,125 

29-069 

9-454 

•001183 

926857 

513 

846 

715,716 

605,495,736 

29-086  !  9-458 

•001182 

927370 

513 

847 

717,409 

607,645,423 

29-103 

9-461 

•001181 

927883 

513 

848 

719,104 

609,800.192 

29-120 

9-465 

•001179 

928396 

512 

849 

720,801 

611,960,049 

29-138 

9-469 

•001178 

928908 

511 

850 

722,500 

614,125,000 

29-155 

9-473 

•001176 

929419 

511 

851 

724.201 

616.295.051 

29-172 

9-476 

•001175 

929930 

510 

852 

725,«»04 

618.470,208 

29-189 

9-480 

•001174 

930440 

509 

853 

727,609 

620,650,477 

29-206 

9-483 

•001172 

930949 

509 

854 

729,316 

622,835,864 

29-223 

9-487 

•001171 

931458 

508 

855 

731,025 

625.026,375 

29-240 

9-491 

•001170 

931966 

508 

856 

732,736 

627^222,016 

29-257 

9-495 

•001168 

932474 

507 

857 

734,419 

629,422.793 

29-274 

9-499 

•001167 

932981 

506 

858 

736,164 

631,628,712 

29-292 

9-502 

•001166 

933487 

506 

859 

737,881 

633,839,779 

29-309 

9-506 

•001164 

933993 

505 

860 

739,600 

636,056,000 

29-326 

9-509 

•001163 

934498 

505 

861 

741.321 

638,277,381 

29-343 

9-513 

•001161 

935003 

504 

862 

743,044 

640.503^928 

29-360 

9-517 

•001160 

935507 

504 

863 

744,769 

642,735,647 

29-377 

9-520 

•001159 

936011 

503 

864 

746,496 

644,972,544 

29-394 

9-524 

•001157 

93651  4 

502 

865 

748.225 

647,214,625 

29-411 

9-528 

•001156 

937016 

502 

866 

749,956 

649,461,896 

29-428 

9-532 

•001155 

937518 

501 

867 

751,689 

651,714,363 

29-445 

9-535 

•001153 

938019 

501 

868 

753,42N4 

653,972,032 

29-462 

9-539 

•001152 

938520 

500 

869 

755,161 

656,234,909 

29-479 

9-543 

•001151 

939020 

499 

870 

756,900 

658,503,000 

29-496 

9-546 

•001149 

939519 

499 

871 

758,641 

660,776,311 

29-513 

9-550 

•001148 

940018 

498 

872 

760,384 

663,054,848 

29-529 

9-554 

•001147 

940516 

498 

873 

762,129 

665,388,617 

29-546 

9-557 

•001145 

941014 

497 

874 

763,876 

667,627,624 

29-563 

9-561 

•001144 

941511 

497 

875 

765,625 

669,921,875 

29-580 

9-565 

•001143 

942008 

496 

876 

767,376 

672,221,376 

29-597 

9-568 

•001142 

942504 

496 

877 

769,129 

674,526,133 

29-614 

9-572 

•001140 

943000 

495 

878 

770,884 

676,836,152 

29-631 

9-575 

•001139 

943495 

494 

879 

772,641 

679,151,439 

29-648 

9-579 

•001138 

943989 

494 

880 

774,400 

681,472,000 

29-0(55  9-583 

•001136 

944483 

493 

881 

776,161 

683,797,841 

29-682  9-586  -001135 

944976 

493 

882 

777.924 

686,128,96« 

29-698  9-590  -001134 

945469 

492 

883 

779,689 

688,465,387 

29-715  9-594  -001133 

945961 

491 

884 

781,456 

690,807,104 

29-732  9-597  -001131 

946452 

491 

GENERAL   MATHEMATICAL   TABLES. 


21 


No. 

Square. 

Cube. 

Square 
Boot. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

885 

783,225 

693,154,125 

29-749 

9-601 

•001130 

946943 

490 

886  !  784,996 

695,506,456 

29-766 

9-604 

•001129 

947434 

490 

887 

786,769 

697,864,103 

29-782 

9-608 

•001127 

947924 

489 

888 

788,544 

700,227,072 

29-799 

9-612 

•001126 

948413 

489 

889 

790,321 

702,595,369 

29-816 

9-615 

•001125 

948902 

488 

890 

792,100 

704,969,000 

29-833 

9-619 

•001124 

949390 

488 

891 

793,881 

707,347,971 

29-850 

9-623 

•001122 

949878 

487 

892  795,664 

709,732,288 

29-866 

9-626 

•001121 

950365 

486 

893  797,449 

712,121,957 

29-883 

9-630 

•001120 

950851 

486 

894  799,236 

714,516,984 

29-900 

9-633 

•001119 

951338 

485 

895  801,025 

716,917,375 

29-916 

9-637 

•001118 

951823 

485 

896  ;  802,816 

719,323,136 

29-933 

9-640 

•001116 

952308 

484 

897  |  804,609 

721,734,273 

29-950 

9-644 

•001115 

952792 

484 

898  806,404 

724,150,792 

29-967 

9-648 

•001114 

953276 

484 

cqn 

OOv/ 

808,201 

726,572,699 

29-983 

9-651 

•001112 

953760 

483 

900 

810,000 

729,000,000 

30-000 

9-655 

•001111 

954243 

482 

901 

811,801 

731,432,701 

30-017 

9-658 

•001110 

954725 

482 

902 

813,604 

733,870,808 

30-033 

9-662 

•001109 

955207 

481 

903  815,409 

736,314,327 

30-050 

9-666 

•001107 

955688 

480 

904  817,216 

738,763,264 

30-066 

9-669 

•001106 

956168 

480 

905  819,025 

741,217,625 

30-083 

9-673 

•001105 

956649 

479 

906 

820,836 

743,677,416 

30-100 

9-676 

•001104 

957128 

479 

907 

822,649 

746,142.643 

30-116 

9-680 

•001103 

957604 

478 

908 

824,464 

748,613^312 

30-133 

9-683 

•001101 

958086 

478 

909 

826,281 

751,089,429 

30-150 

9-687 

•001100 

958564 

477 

910 

828,100 

753,571,000 

30-163 

9-690 

•001099 

959041 

477 

911 

829,121 

756.058,031 

30-183 

9-694 

•001098 

959518 

477 

912 

831,744 

758,550,528 

30-199 

9-698 

•001096 

959995 

476 

913 

833,569 

761,048,497 

30-216 

9-701 

•001095 

960471 

475 

914 

835,396 

763,551,944 

30-232 

9-705 

•001094 

960946 

475 

915 

837,225 

766,060,875 

30-249 

9-708 

•001093 

961421 

474 

916 

839,056 

768,575,296 

30-265 

9-712 

•001092 

961895 

474 

917 

840,889 

771,095,213 

30-282 

9-715 

•001091 

962363 

474 

918 

842,724 

773,620,632 

30-298 

9-718 

•001089 

962843 

473 

919 

844,561 

776,151,559 

30-315 

9-722 

•001088 

963316 

473 

920 

846,400 

778,688,000 

30-331 

9-726 

•001087 

963788 

472 

921 

848,241 

781,229,961 

30-348 

9-729 

•001086 

964260 

471 

922 

850,084 

783,777,448 

30-364 

9-733 

•001085 

964731 

471 

923 

851,929 

786,330,467 

30-381 

9-736 

•001083 

965202 

470 

924 

853,776 

788,889,024 

30-397 

9-740 

•001082 

965672 

470 

925 

855,625 

791.453,125 

30-414 

9-743 

•001081 

966142 

469 

926 

857,476 

794,022,776 

30-430 

9-747 

•001080 

966611 

469 

927 

859,329 

796,597,983 

30-447 

9-750 

•001079 

967080 

468 

928 

861,184 

799,178.752 

30-463 

9-754 

•001078 

967548 

468 

929 

863,041 

801.765,089 

30-479  !  9-757 

•001076 

968016 

467 

GAS  ENGINEER'S  POCKET-BOOK. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

930 

864,900 

804,357,000 

30-496 

9-761 

•001075 

968483 

467 

931 

866,761 

806,954.491 

30-512 

9-764 

•001074 

968950 

466 

932 

868,624 

809,557,568 

30-529 

9-768 

•C01073 

969416 

466 

933 

870,489 

812,166.237 

30-545 

9-771 

•001072 

969882 

465 

934 

872,356 

814,780.504 

30-561 

9-775 

•001071 

970347 

465 

935 

874,225 

817,400,375 

30-578 

9-778 

•001070 

970812 

464 

936 

876,096 

820,025,856 

30-594 

9-783 

•001068 

971276 

464 

937 

877,969 

822,656,953 

30-610 

9-785 

•001067 

971740 

463 

938 

879,844 

825,293,672 

30-627 

9-789 

•001066 

972203 

463 

939 

881,721 

827,936,019 

30-643 

9-792 

•001065 

972666 

462 

940 

883,600 

830,584.000 

30-659 

9-796 

•001064 

973128 

462 

941 

885,481 

883,237,621 

30-676 

9-799 

•001063 

973590 

461 

942 

887,364 

835,896.888 

30-692 

9-803 

•001062 

974051 

461 

943 

889,249 

838,561,807 

30-708 

9-806 

•001060 

974512 

460 

944 

891,136 

841.232,284 

30-724 

9-810 

•001059 

974972 

460 

945 

893,025 

843,908,625 

30-741 

9-813 

•001058 

975432 

459 

946 

894,916 

846,590,536 

30-757 

9-817 

•001057 

975891 

459 

947 

896.809 

849.278,123 

30-773 

9-820 

•001056 

976350 

458 

948 

898,704 

851,971,392 

30-790 

9-823 

•001055 

976808 

458 

949 

900,601 

864,670,349 

30-806 

9-827 

•001054 

977266 

457 

950 

902,500 

857,375,000 

30-822 

9-830 

•001053 

977724 

457 

951 

904,401 

860,085,351 

30-838 

9-834 

•001052 

978181 

456 

952 

906,304 

862,801.408 

30-854 

9-837 

•001050 

978637 

456 

953 

908,209 

865,523,177 

30-871 

9-841 

•001049 

979093 

455 

954 

910,116 

868,250,664 

30-887 

9-844 

•001048 

979548 

455 

955 

912,025 

870,983.875 

30-903 

9-848 

•001047 

980003 

455 

956 

913,936 

873,722,816 

30-919 

9-851 

•001046 

980458 

454 

957 

915,849 

876,467,493 

30-935 

9-854 

•001045 

980912 

454 

958 

917,764 

879,217,912 

30-951 

9-858 

•001044 

981366 

453 

959 

919,681 

881,974,079 

30-968 

9-861 

•001043 

981819 

452 

960 

921,600 

884,736,000 

30-984 

9-865 

•001042 

982271 

452 

961 

923,521 

887,503,681 

31-000 

9-868 

•001041 

982723 

452 

962 

925,444 

890,277,128 

31-016 

9-872 

•001040 

983175 

451 

963 

927,369 

893,056,347 

31-032 

9-875 

•001038 

983626 

451 

964 

929,296 

895,841,344 

31-048 

9-878 

•001037 

984077 

450 

965 

931,225 

898,632,125 

31-064 

9-881 

•001036 

984527 

450 

966 

933,156 

901,428,696 

31-080 

9-885 

•001035 

984977 

449 

967 

935,089 

904,231,063 

31-097 

9-889 

•001034 

985426 

449 

968 

937,024 

907,039,232 

31-113 

9-892 

•001033 

985875 

449 

969 

938,961 

909,853,209 

31-129 

9-895 

•001032 

986324 

448 

970 

940,900 

912,673,000 

31-145 

9-899 

•001031 

986772 

447 

971 

942,841 

915,498,611 

31-161 

9-902 

•001030 

987219  !  447 

972 

944,784 

918,330,048 

31-177 

9-906 

•001029 

987666  447 

973 

946,729 

921,167,317 

31-193 

9-909 

•001028 

988113  !  446 

974 

948,676 

924,010,424 

31-209 

9-912 

•001027 

988559 

446 

GENERAL  MATHEMATICAL  TABLES. 


23 


No. 

Square. 

ICube. 

Square 
Root. 

Cube 
Root. 

Recip- 
rocal. 

Loga- 
rithm. 

Differ- 
ence. 

975 

950,625 

926,859,375 

31-225 

9-916  -001026 

989005 

445 

976;  952,576  929,714,176 

31-241 

9-919  -001025 

989450 

445 

977  954,529  932,574,833 

31-257 

9-923  -001024 

989895 

444 

978  956,484  935,441,352 

31-273 

9-926 

•001022 

990339 

444 

979  958,441  938,313,739 

31-289 

9-929 

•001021 

990783 

443 

980  960,400  941,192,000 

31-305 

9-933 

•001020 

991226 

443 

981  962,361;  944,076,141 

31-321 

9-936 

•001019 

9916-69 

442 

982  964,324 

946,966,168 

31-337 

9-940 

•001018 

992111 

442 

983  966,289 

949,862,087 

31-353 

9-943 

•001017 

992554 

441 

984  968,256 

952,763,904 

31-369 

9'946 

•001016 

992995 

441 

985  970,225 

955,671,625 

31-385 

9-950 

•001015 

993436 

441 

986  972,196 

958,585,256 

31-401 

9-953 

•001014 

993877 

440 

987 

974,169 

961,504,803 

31-416 

9-956 

•001013 

994317 

440 

988 

976,144 

964,430,272 

31-432 

9-960 

•001012 

994757 

439 

989 

978,121 

967,361,669 

31-448 

9-963 

•001011 

995196 

439 

990 

980,100 

970,299,000 

31-464 

9-966 

•001010 

995635 

439 

991 

982,081  973,242,271 

31-480 

9-970 

•001009 

996074 

438 

992 

984,064  976,191,488 

31-496 

9-973 

•001008 

996512 

437 

993 

986,049  979,146.657 

31-512 

9-977 

•001007 

996949 

437 

994 

988,036  982,107,784 

31-528 

9-980 

•001006 

997386 

437 

995 

990,025  985,074,875 

31-544 

9-983 

•001005 

997823 

436 

996  992,016  988,047,936 

31-559 

9-987 

•001004 

998259 

436 

997 

994,009  991,026,973 

31-575 

9-990 

•001003 

998695 

435 

998 

996,004,  994,011,992 

31-591 

9-993 

•001002 

999131 

434 

999 

998,001  997,002.999 

31-607 

9-997 

•001001 

999565 

1000 

1.000.0001,000,000,000 

31-623  10-000 

•001000 

The  common  Logarithm  of  any  number  is  the  power  to  which,  if 
10  be  raised,  the  said  number  is  the  result  thus  : — 

102         =  100  therefore  Log.  =  2- 
102-42      =  263         „  „      =  2-42 

10-2-42  =  .0263      „  „      =2-42 

To  multiply  by  the  aid  of  logarithms— add  the  logarithms  of  the 
numbers  together  and  find  the  corresponding  number  of  the  logarithm 
obtained. 

To  divide  lij  the  aid  of  logarithms— subtract  one  logarithm  from  the 
other. 

To  extract  any  root — divide  the  logarithm  by  the  index  of  the  root 
and  find  the  corresponding  number  of  the  logarithm  obtained. 

To  raise  a  number  to  any  power — multiply  the  logarithm  of  the 
number  by  the  index  of  the  power,  and  find  the  corresponding 
number  of  the  logarithm  obtained. 

To  fi?id  proportion  by  the  aid  of  logarithms — add  together  the 
logarithms  of  the  second  and  third  terms  and  subtract  the  logarithm 
of  the  first  term ;  the  answer  is  the  corresponding  number  of  the 
logarithm  obtained. 


GAS  ENGINEER'S  POCKET-BOOK. 
Areas  and  Circumferences  of  Circles. 


AREAS  AND    CIRCUMFERENCES   OF   CIRCLES.  25 


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30 


GAS  ENGINEER'S  POCKET-BOOK. 


B  oo  O  «*  04  oe  "«  <    t«  «    O  O  J-H  «Q  «  te^a    O»  O 


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ARE  Ad    AND    CIRCUMFERENCES    OF    CIRCLES.  31 


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32 


GAS  ENGINEER'S  POCKET-BOOK. 


ic  cc  oo  cs  o  r—  (c 


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AREAS    AND    CIRCUMFERENCES    OF    CIRCLES. 


33 


G.E. 


GAS    ENGINEERS   POCKET-UUOK. 


10    6r 

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AREAS   AND   CIRCUMFERENCES   OF   CIRCLES.  35 


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36 


GAS  ENGINEER'S  POCKET-BOOK. 


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AREAS   AND   CIRCUMFERENCES   OF   CIRCLES.  37 


CO  CO  CO  CO  CO  CO  CO  tO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO 


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GAS   ENGINEER'S  POCKET-BOOK. 


AREAS   AND    CIRCUMFERENCES   OF   CIRCLES.  39 


0) 


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40 


GAS  ENGINEER'S  POCKET-BOOK. 


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PROPERTIES    OF    THE    CIRCLE. 


41 


To  find  Area  of  a  Segment  of  a  Circle. — From  the  area  of  a  sector 
having  same  arc  subtract  the  area  of  triangle  whose  2  sides  =  radius 
of  circle  and  base  =  chord  of  segment. 

The  volume  of  a  sphere  =  diameter  3  x  -5236. 

Area  of  oval  =  major  diameter  x  minor  diameter  X  '7854. 

To  find  the  Length  of  a  Side,  the  diameter  being  given  : — 

For  a  Hexagon,  multiply  the  diameter  by  *577 
Octagon,          „        .  .,  „          „    '414 

Decagon,         „  „  „          „    -325 

Dodecagon,     „  ,,  „          „    -268 

The  square  of  any  number  containing  a  fraction  equals  the  whole 
number  multiplied  by  its  next  higher  digit  -4-  the  square  of  the 
fraction,  as  follows  :— 

2  =  8  X  9  +1 
2  =  8  X  8J  +  i 
2  =  8  X  8i  + 


Properties  of  the  Circle. 

Circumference  =  diameter  X  3-1416  or  3i. 
Diameter  x  '8862  =  side  of  equal  square. 
Diameter  x  '7071  =      „       inscribed  square. 
Diameter2  X  '7854  =  area  of  circle. 
Length  of  arc  of  circle  =  no.  of  degrees  X  "017453. 


f —  Cosine 
»— Radius 


GAS  ENGINEER'S  POCKET-BOOK. 


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MEASURES    OF    LENGTH. 


43 


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44  GAS  ENGINEER'S  POCKET-BOOK. 

Square  yards  X  '000000323  =     square  miles. 

Acres    *  X  '0015625  =          „          ,, 

27,878,400  square  feet  =  1     „         ,, 

3,097,600  square  yards  =  1     ,.          „ 

640  acres    *  =  1     „         „ 

2-471143     „  =  1  hectare. 

1     „  =  10  square  chains. 

1  chain  wide  =  8  acres  per  mile. 


Cubic  Measure. 

inches.  feet.  yards.  cubic  metres. 

1  =      -0005788  =    -00002144  =  -00001638(5 
1,728=    1  =    -03704        =-028315 

46,656  =  27  =1  =  -764513 


Ale  and  Beer  Measure  (used  for  ammoniacal  liquor). 

gills. 

4  =      1  pint. 
8  =      2  =      1  quart. 
32  =      8  =      4  =      1  gallon. 
288  =    72  =    36  =      9=1  firkin. 
576  =  144  =    72  =    18  =    2  =  1  kilderkin. 
1,152  =  288  =  144  =    36  =    4  =  2  =  1  barrel. 
1,728  =  432  =  216=    54=    6  =  3  =  1-5  =  1  hogshead. 
2,304  =  576  =  288  =    72  =    8  =  4  =  2     =1-3=1  puncheon. 
:<,356  =  864  =  432  =  108  =  12  =  6  =  3     =2     =  1-5  =  1  butt. 


Measures  of  Capacity,  or  Dry  Measure. 

pints,    galls.       pecks,     bushels,    quarters,    weys.  last.       cubic  feet.       litres. 

1=       -125-       -0625=     -01562=     -00195=   -00039=  -000195=       -020051=.         -5679 

8=1        =       -5       =     -125     =     -0156  =    -00312=  '00156  =       -16046  =       4'543 

16=     2        =1          =     -25       =     -03125=   -00625=  -00312  =       -32092  =       9'087 

64=8        =     4          =1  =     -125     =   -025     =  "0125  =     1-28367  =     36-347C6 

512=  64        =32          =8  =1  =    '2         =  '1  =   10'269       =   290'781 

2560=320]       =160          =40  =5  =1  =  '5  =  51-347       =1453'906 

3120=640        =320          =80  =10  =2  =1  =102'69        =2907'81 

Cubic  inches  X  '028848      =  pints. 
„  „       X  '014424      =  quarts. 

„  „  X  -003606  =  gallons. 
„  „  x  -0004508  =  bushels. 
„  „  X  -00005635  =  quarters. 

1  pint     =    34-66    cubic  inches. 

1  gallon  =  277-27384  cubic  inches  =  10  Ibs.  distilled  water. 

Cubic  feet       X  6-2355      =  gallons. 

Cubic  inches  X  -003607  =      „ 

Cubic  feet      X  '78         =  bushels. 

Cubic  inches  x  -00045    =      „ 


DECIMALS   OF   £1    STERLING. 


45 


Decimals  of  £1  Sterling. 


Pence  and 

id. 

«  j 

Shillings. 

Jd. 

|d. 

0 

•0010416 

•002083 

•003125 

1 

•00416 

•0052083 

•00625 

•00729^6 

2 

•0083 

•009375 

•010416 

•0114583 

3 

•0125 

•0135416 

•014583 

•015625 

4 

•016 

•0177083 

•01875 

•0197916 

5 

•02083 

•021875 

•022916 

•0239583 

6 

•025 

•026416 

•027083 

•028125 

7 

•02916 

•0302083 

•03125 

•0322916 

8 

•03 

•034375 

•035416 

•0364583 

9 

•0375 

•0385416 

•039583 

•040625 

10 

•0416 

•0427083 

•04375 

•0447916 

11 

•04583 

•046875 

•0479J6 

•0489583 

1-0 

•05 

•0510416 

•052083 

•053125 

1-1 

•05416 

•0552083 

•05625 

•0572916 

1-2 

•0583 

•059375 

•060416 

•0614583 

1-3 

•0625 

•0635416 

•064583 

•065625 

1-4 

•06 

•0677083 

•06875 

•0697916 

1-5 

•07083 

•071875 

•072916 

•0739583 

1-6 

•075 

•0760416 

•077083 

•078125 

1-7 

•07916 

•0802083 

•08125 

•0822916 

1-8 

•085 

•084375 

•085416 

•0864583 

1-9 

•0875 

•0885416 

•089583 

•090625 

MO 

•0916 

•0927083 

•09375 

•0947916 

1-11 

•09583 

•096875 

•097916 

•0989583 

2-0 

•1 

8-0 

•4 

14-0      '7 

3-0 

•15 

9'0 

•45 

15-0      -75 

4-0 

•2 

10-0 

•5 

16-0      '8 

5-0 

•25 

11-0 

•55 

17-0      '85 

6-0 

•3 

12-0 

•6 

18-0      '9 

7-0 

•35 

13-0 

•65 

19-0     '95 

To  Convert  £  s.  d.  into  Decimals  of  £1  by  Inspection  (approxi- 
mately).—Place  the  £'s  before  the  decimal  point ;  in  the  first  place, 
after  the  decimal  point,  insert  the  florins  or  half  the  even  number  of 
shillings ;  fill  the  second  and  third  places  with  the  number  of  farthings 
in  any  odd  shilling,  pence,  and  farthings,  adding  thereto  1  if  the 
number  of  farthings  be  24,  2  if  48,  and  3  if  72  or  more  (the  number 
of  farthings  can  never  amount  to  96,  because  96  farthings =2/-='l). 

By  this  rule  the  error  cannot  amount  to  1  farthing. 


46 


GAS  ENGINEER'S  POCKET-BOOK. 


Decimals  of  1  Cwt. 


0 

Qrs. 

Qrs. 

Qrs. 

1 

2 

3 

0 

•25 

•5 

•75 

1 

•008928 

•258928 

•508928 

•758928 

2. 

•017857 

•267857 

•517857 

•767857 

3 

•026786 

•276786 

•526786 

•776786 

4 

•035714 

•285714 

•535714 

•785714 

5 

•044643 

•294643 

•544643 

•794643 

6 

•O.")3571 

•303571 

•553571 

•803571 

7 

•0625 

•3125 

•5625 

•8125 

8 

•071458 

•321458 

•571458 

•821458 

9 

•080357 

•330357 

•580357 

•830357 

10 

•089286 

•339286 

•589286 

•839286 

11 

•098214 

•348214 

•598214 

•848214 

12 

•107143 

•357143 

•607143 

•857143 

13 

•116071 

•366071 

•616071 

•866071 

14 

•125 

•375 

•625 

.  -875 

15 

•133928 

•383928 

•633928 

•883928 

16 

•142856 

•392856 

•642856 

•892856 

17 

•151785 

•401785 

•651785 

•901785 

18 

•160714 

•410714 

•660714 

•910714 

19 

•169643 

•419643 

•669643 

•919643 

20 

•178572 

•428572 

•678572 

•928572 

21 

•1875 

•4375 

•6875 

•9375 

22 

•196428 

•446428 

•696428 

•946428 

23 

•205357 

•455357 

•705357 

•955357 

24 

•214286 

•464286 

•714286 

•964286 

25 

•223214 

•473214 

•723214 

•973214 

26 

•232143 

•482143 

•732143 

•982143 

27 

•241071 

•491071 

•741071 

•991071 

Ozs. 

Ozs. 

Ozs. 

1 

•000558 

7 

•003906 

13 

•007254 

2 

•001116 

8 

•004464 

14 

•007812 

3 

•001674 

9 

•005023 

15 

•008370 

4 

•002232 

10 

•005580 

i 

•000139 

5 

•002790 

11 

•006138 

•000279 

6 

•003348 

12 

•006696 

f 

•000418 

DECIMAL   EQUIVALENTS. 
Decimals  of  1  Mile. 


47 


500  yards 
400  „ 

•284091 
•227222 

20  yards 
10  , 

•011364 
•005682 

1  foot 
11  inches 

•0001894 
•000174 

300  „ 

•170454 

9  , 

•005114 

10 

•000158  ' 

200  „ 

•113030 

8  , 

•004545 

9 

•000142 

100  „ 

•056818 

7  , 

•003977 

8 

•000126 

90  „ 

•051136 

6  , 

•003409 

7 

•000111 

80  „ 

•045454 

5   , 

•002841 

6 

•000095 

70  „ 

•039773 

4  , 

•002273 

5 

•000079 

60  „ 

•034091 

3  , 

•001704 

4 

•000063 

50  „ 

•028409 

2  „ 

•001136 

3 

•000047 

40  „ 

•022727 

1   „ 

•000568 

2   , 

•000032 

30  „ 

•017045 

2  feet 

•000379 

1 

•000016 

Decimals  of  1  Year  of 


Days. 


300  days 

•821918 

9  days 

•024657 

9  hours 

•001026 

200  „ 

•547945 

8 

•021918 

8  „ 

•000912 

100  „ 

•273975 

7 

•019178 

7  „ 

•000798 

90  „ 

•246575 

6 

•016438 

6  „ 

•000684 

80  „ 

•219178 

5 

•013698 

5  .„ 

•000576 

7P  „ 

•191781 

4 

•010959 

4  „ 

•000456 

60  „ 

•164383 

3 

•008219 

3  „ 

•000342 

50  „ 

•136986 

2 

•005479 

2  „ 

•000228 

40  „ 

•109589 

1   , 

•002739 

1  „ 

•000114 

30  „ 

•082192 

12  hours 

•001369 

I  » 

•000085 

20  „ 

•054794 

11  „ 

•001254 

*  „ 

•000057 

10  „ 

•027397 

10  „ 

•001140 

In 

•000028 

Decimal  Equivalents  of  an  Inch. 


J?               -015625 

y 

•34375 

fl 

•671875 

&         -03125 

B 

•359375 

£ 

•6875 

£ 

•046875 

.     I 

•375 

£ 

•703125 

* 

•0625 

a 

•390625 

a 

•71875 

6 

•078125 

a 

•40625 

i 

•734375 

•09375 

a 

•421875 

i 

•75 

* 

•109375 

i7s 

•4375 

55 

•765625 

i 

•125 

11 

•45312'5 

H 

•78125 

A 

•140625 

M 

•46875 

fi 

•796875 

A 

•15625  »' 

il 

•484375 

a 

•8]  25 

tt 

•171875 

i 

•5 

1! 

•828125 

A 

•1875 

8 

•515625 

i 

•84375 

a 

•203125 

it 

•53125 

if  ^ 

•859375 

& 

•21875 

if 

•546875 

•875 

$ 

•234375 

A 

•5625 

8 

•890625 

} 

•25 

8 

•578125 

a 

•90625 

ti 

•265625 

H 

•59375 

n 

•921875 

A 

•28125 

if 

•609475 

a 

•9375 

a 

•296875 

I 

•J625 

a 

•953125 

A 

•3125 

tt 

•640625 

fi 

•96875 

8 

•328125 

H 

•65625 

a 

•984375 

48 


GAS    ENGINEERS    POCKET-BOOK, 


Inches  and  Fractions  of  Inches  in  Decimals  of  1  foot. 


0 

1 

2 

3 

4 

5 

6 

7    |    8       9 

10 

11 

0 

•oooo 

•0833 

•1667 

•2500 

•3333 

•4167 

•5000 

•5833  i'6667  "'7500 

•8333 

•9167 

A 

•0026  '0859'  -1693 

•2526 

•3359 

•4193«  -5026 

•5859  |'6693   '7526 

•8359 

•9193 

,  A 

•0052  i'0885   -1719 

•2552 

•3385 

•4219   -5052 

•5885    '6719   -7552 

•8385 

•9219 

A 

•0078  i'0911 

•1745 

•2578 

•3411 

•4245 

•5078 

•5911  j-6745   -7578 

•8411 

•9245 

I 

•0104  i-0938  -1771 

•2604 

•3438 

•4271 

•5104 

•5938  >6771   '7604 

•8438 

•9271 

tf 

•0130   '0964 

•1797 

•2630 

•3464 

•4297 

•5130 

•5964   -6797  '7630 

•8464 

,•9297 

•0156   -0990  -1823 

•2656 

•3490 

•4323  '-5156 

•5990   -6823  '7656 

•8490 

•9323 

T        » 
32 

•0182   -1016 

•1849 

•2682 

•3516 

•4349  '  -5182 

•6016  ,'6849  >7682 

•8516 

•9349 

i 

•0208 

•1042 

•1875 

•2708 

•3542 

•4375  1-5208 

•6042   -6875  ,'7708 

•8542 

•9375 

A  * 

•0234 

•1068 

•1901 

•2734 

•3568 

•4401  i  '5234 

•6068  ,-6901   '7734 

•8568 

•9401 

A 

•0260  I-1094 

•1927 

•2760 

•3594 

•4427 

•5260 

•6094  -6927   '7760 

•8594 

•9427 

tt 

•0286   1120  '1953 

•2786 

•3620 

•4453 

•5286 

•6120  -0953   '7786 

•8620 

•9453 

i 

•0313 

•1146  i'1979 

•2813 

•3646 

•4479 

•5313 

•6146   '6979  i'7813 

•8646 

•9479 

It  7 

•0339 

•1172 

•2005 

•2839 

•3672 

•4505 

•5339 

•6172  j-7005  |-7839 

•8672 

•9505 

T?ff 

•0365 

•1198 

•2031 

•2865 

•3698 

•4531 

•5365 

•6198   -7031 

•7865* 

•8698 

•9531 

ft 

•0391 

•1224 

•2057 

•2891 

•3724 

•4557 

•5391 

•6224  '7057 

•7891 

•8724 

•9557 

i 

•0417 

•1250 

•2083 

•2917 

•3750 

•4583 

•5417 

•6250 

•7083 

•7917 

•8750 

•9583 

tt 

•0443 

•1276 

•2109 

•2943 

•3776 

•4609   -5443 

•6276   '7109   -7943 

•8776 

•9609 

ft 

•0469  |-1302 

•2135 

•2969 

•3802 

•4635    '5469 

•6302   '7135   -7969 

•8802 

•9635 

H 

•0495  i-1328 

•2161 

•2995 

•3828 

•4661    '5495 

•6328 

•7161 

•7995 

•8828 

•9661 

1 

•0521    -1354 

•2188 

•3021 

•3854 

•4688  j-5521 

•6354 

•7188 

•8021 

•8854 

•9688 

tt 

•0547  :-1380 

•2214 

•3047 

•3880 

•4714   -5547 

•6380 

•7214 

•8047 

•8880 

•9714 

H 

•0573   -1406 

•2240 

•3073 

•3906 

•4740   -5573 

•6406 

•7240 

•8073 

•8906 

•9740 

If 

•0599  ;1432 

•2266 

•3099 

•3932 

•4766 

•5599 

•6432 

•7266 

•8099 

•8932   -9766 

I 

•0625   '1458   '2292 

•3125 

•3958 

•4792 

•5625 

•6458 

•7292 

•8125 

•8958 

•9792 

it 

•0651 

•1484  i  -2318 

•3151 

•39S4 

•4818 

•5651 

•6484 

•7318 

•8151 

•8984 

•9818 

H 

•0677   '1510  i'2344   '3177 

•4010 

•4844 

•5677 

•6510 

•7344 

•8177 

•9010 

•9844 

H 

•0703   -1536   '2370    '3203 

•4036 

•4870   '5703 

•6536 

•7370 

•8203 

•9036 

•9870 

1 

•0729  >1563  ;-2396 

•3229 

•4063 

•4896   -5729 

•6563 

•7396 

•8229 

9063 

•9896, 

« 

•0755  1-1589  1-2422 

•3255* 

•4089 

•4922 

•5755 

6589 

•7422 

•8255 

9089 

•9922 

if    -0781   -1615  -2448 

•3281 

•4115 

•4948 

•5781 

6615 

7448 

•8281 

9115 

•9948 

H 

•0807 

•1641 

•2474 

•3307 

•4141 

•4974 

•5807 

6641. 

•W4  -8307 

9141 

•9974 

Ounces  in  Decimals  of  1  Ib. 


Ozs. 

"Lbs. 

Ozs. 

Lbs. 

Ozs. 

Lbs. 

i 

•015625 

5 

•3125 

104 

•65625 

i 

•03125 

5£ 

•34375 

11 

•6875 

I 

•046875 

6 

•375 

114 

•71875 

1 

•0625 

6* 

•40625 

12 

•75 

H 

•09375 

7 

•4375 

12| 

•78125 

2 

•125 

7i 

•46875 

13 

•8125 

2* 

•15625 

8 

•5 

tat 

•84375 

3 

•1875 

8| 

•53125 

14 

•875 

S| 

•21875 

9 

•5625 

14i 

•90625 

4 

:25 

9ft 

•59375 

15 

•9375 

^ 

•28125 

10 

•625  • 

M| 

•9687 

DECIMALS   OF    1    TON. 
Decimals  of  1  Ton, 


COCOOlCOC^OOuSi-HaO^rHt^-*          CO  CO          COC<IOOU5i-IGO^.-lOS'*< 
•*HO5COGOCOt~CNlt>-i—  I  «O  i—  llQOlCOS''*iOSCOCOC<It>C<ICOi—  I  CO  O  Ui 

»OOSCOGCC<lt-rHCOOiQOS''*<GOeOt-r-  <COOlO 

t>t>>COOOOSOSOOi—  1  i—  li-HCNCNlCO?O^I'^iOlO 


COOSCO<NGOiO.-IOO-*rM«>-*          CO  CO          «O<NOOlOrHOO"*i-lO>-* 


tO<NOOlOi-IOO"«*rHOi 
OiCOQOlMrr-fN^Oi-HtOO 
iOO'*O5COQO<Nt~i-(«O 
i-l<NC^CCCC^^H^J«lO?O«Ot^«>-OOOOOOOSOlOOrHT-H 
OOOOOOOOOOOOOOOOOOOrHr-(rH^H 


co 


GO  GO  GO  GO  GO  CC  OS  OS  OS  OS  OS  OS  OS 
O  O  O  O  O  O  O  O  O  O  O  O  O 


CO  CO  t^  l>" 


COCOOSCO(NQO>Oi—  (QO-^i—  I 


COCOOSCO<MGO»«!-IOO'*i-lt^'*         COCO         CO(MOOU5r-HGO'*rHOSitl 


^H  CO  O  lO  OS  "^  GO 

(NC^lCOCO-^H-^iOUSCOCOCOt^t-COGOOsOSOOOf-lr-l......  .       . 

cocococococococococococococccccocot—  t^  t~  t~  t—  t^t^t^P^t-t^ 


OCOCOCOCO^^^^^'^'^-^'^'^^-^-^-T**^^I*t<'**l-*t<'*f!Ttl'Tt< 

ooooopoooooooooooooooooooo 


COCO          «O(NOO»CT-IGO'*f-lOS'* 


COCOOSCO(NQO>OrHOO-*i-tl>"*         COCO 
"*O5COCOCOt><Nt^T-iCO^-IU5OU5OS-* 


1-Hi-HrHi-Hi-^i-Hi— (i— (C<JC^CNe<>WC<IC<)e<IC<JC<J 

oooooooooooooooooo 


COCOOSCOWGOlOi—  IGO-^T—  (t^1*          COCO 


COCO 
^OS 


OOr—  li—  <C<lC<lJOCO'^"*'^l»CU5COCOt--t-GOGOQOOSOSOOi—  li-^C<l 

SOOOOOOOOOOOOOOOOOOOOOrH^Hi—  ii-l-^ 
oooooooooooooooooooooooooo 


50 


GAS  ENGINEER'S  POOKET-BOOK. 


tCCOO-tO'NGOiC--3DH 

-*<OSCOOOCOt-O-}t>-i— i  «£ 

»C  OS  CO  GO  <M  !>•  i— I  CO  O  1C  O 


t>-*    tOCO    O  !M  CO  »C 
00  CO  t^  i-l  tO  O 


eo 

aOGOOOCOODCOOSOsOSOS 
O-l  C~^  C1! 

tOCOOStO<MCClC.-IOO--ii-lt> 

-*oscppocot--c<ii>-»^<tp'7-<ic>' 

N  65  c<i  e5 

it 

CO 

OS  CO 

O  O 

t^  b- 

tOCO  tO<NCOlCi-HGO^>— I  OS  •**< 
COS^OSCOGOC^t^fNtOi-HtOOtC 
>J-0^-l>CO-*O.COCO(Mt--r-<tOO 

tOCOO5«O<NGOiOi-IGO~-tlr-lt~-*          tOCO 
-*OJCOGOCOt-<Mt--rHtOi-HlCiOiCOl'* 

CO 
CM 

T^l 

OOi-H>— (<M<_<ICOCO'*i 

O  O  O  2  ^H  _  .  _  . 

C^(^(NM^(N^<N^M^^^^^fj^<^(NC<l<NC<><N'^l 

«o  co  ci  i 

^  OS  CO 
w        >f.O-COCO<Mt^i-H' 

00  GO  GO  GO  GO  GO  Oi  O5  O5  Oi  OS  OS  OS  OS  OS  OS  O-  OS  OS  OS  OS  OS  OS  Oi  OS  OS  OS  OS 

i^KK^Pt>;^P^i^t^^o6oobq<x)opopopocopeocooo 

CO 

1C  OS  CO  OO  C^l  t^*  i~H  tO  O  >C  OS  ^  GO  CO  t^~  *~^  tO  O  *C  OS  "^  GC  CO  ^^*  C^ 

£o  to  to  to  to  to  to  to  to  to  to  to  to  to  to  to  to  t^  i>*  t^*  ^  i>*  t'*  f*  t^* 

tOCOO5tOC<lOOiCi— lOO-^li— It--*          tOCO          tCC<ICO»Ci-HCO-tl 

O          -tioscoaoOTt^e^t-'rHtOT^iooicos-t'OjicoGocjt; 

en 

"g      w    »C  10  »C  1C  S  1C  »C  >C  i£  >C  1C  1C  »C  1C  »C  1C  1C  »C  »C  XC  1C  S  1C  tO  O  to|  tO  tO 

o 


DECIMALS    OF    1    TON. 


51 


iCC;cOGCi?-lt>'rHCOOiCC}''±lCOCCt>t'—  iCOCiC 
t^-  l>-  QC  GO  O  O3  O  O  r—  I  i—  I  i—  !  C^l  C^  CO  CO  -f  -*<  »C   '~ 


>^  O  «C  l^-  t>-  OO  CO  C5  CS 


«5»o»o«p«ot-t^cccccr.  c^ciOOi-ti-te^cqeoeow^-*»o»o«o«wfr» 

(>1  <M  <M  C<I  <M  <M  <M  iM  C^l  7-J  <M  C^J  rC  CC  CO  CO  CO  CC  CO  CO  CO  CO  CO  CO  CO  CO  1C  CO 


-^HO5MGOCCt-(Nt^--l?C'-HinO»SO5-H35COOO<Nt><M«Oi-ICCO»C 

c  cs  co  co  «M  t^  ^H  o  o  «a  o>  •*  oo  eo  t»  »^  «o  o  >o  o»  ^**  QO  eo  i-  <N  «o  »-i  »o 

-^lCm^tC<iCt^t--QOOOCiCiOOO>—  I  i—  i  <?•!  <M  CC-  CO  -*•«*< 


-*  co  co  i^  (M  co  i—t  »n  o  'ti  c;  co  cc  (M  cc  ^H  ic  o  -*  o  co  GO  IM  i^  T-I  cc 

OOi—  1  i—  (<M(NCOCO-*-^<'+')C   lCC2tri^t--COCCX'C5C5OOi—  tr—  1(7< 


fOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCO 


CO  CO   CS  CO  <M  GO  1C  i— I  GO  -*  i-H  t-  •**<          COCO 

t-t-b-t»t>b-t-t*t-t»t»b-oooOGOooooQ666o6a6QbabooQOooooao 

cocococococococococococococococococococococococococococo 


C^GOlCrHGO-^jHOJ^ 

CO  CO  CO  **  TH  1C  1C  CO  CO  *> 

GOGCGOGOGOGOGOGCCOCO 


<OCOOSCOC<IOO»CT-IQO"*lrHt-"*  «OCO  «C<MCO»Ci—  IGO-*i-IC5-t< 
•^OSCOOOCOt^C^t^i—  ICOi—  |lCO»OC5'*iCSCOGOiMl>-(MCOi—  ICOOlO 
OiCOQO(Mt-i—  l«OOiCC5-+iGOCOt-i—  ICOOiCO-rtHCOCOt^(NCOi—  llO 


-i-i—  CO' 

cocococoeococococococococococococococococococoeococococo 


«OCOC5CO(MCOl«i-ICO-*^Hl>-'*i 


eOCOa>CO<NOOlCi-lGO-*i-lt  --  #  COCO  CO(MCOiCi-HGO'*i-iaS'* 
•rHOSCOCOCOt—  C<Jt>i—  ICOi—  llCOiCO5-*lC5COCOC<ll>-(7<lCOi—  ICOOlO 
iCC5"^CCCOt^'—  ICOOlCOi-^GOCOt^fMCO.-llO 


COCOCOCOCOCO^-*^^-*-*^^^-*-*^^-***-*-*-*-*-*-*-* 

cpcocpwwcp«M«cccpcpcpcpcpcpcocpcpcpc«cospeo«cpepcp 


CCCOClCOC<|CClOi— ICO'*!— I  t»-  "+l          CO 
-tlQOCOt^CXlCOi-llCO-HClCOCOC^CO 

CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO 


(MQOlCi—  ICO'*!rHC5'* 
CO(Mt^(NCOi—  ICOOiC 
C^t-i—  ICCO 


COCOCOfOCOCOCCCOCOCOCOCO 


COCiCO 
aJCOOO 


<MCOlOr-IGO-*T-lt~^H 


^1  CN1  (M  CXI  <?q  <fl  CN  (M  CN  CXJ  <M 

CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO. CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO 


COCOClCOC<IGOiOT-<GO**l?— it-**          CO 
**IC5COOOCOt—  (Mt—  T— ICOi— I1OO1CO5 

ooooooooooooc5oo 


CCCQCOlCi—  ICO^i—  IO5-^I 

COGOC<|t-(I^COr-  (COOlO 
l--i-ICCO 


52 


GAS  ENGINEER'S  POCKET-BOOK. 


-C»— IQO^i— It^'f    COCO 

eo   ^  ~ 

iC  ip  iC  iC  ip  ip  ip  ip i  1C  ip  ip  ip  ip i  ip  ip i  ip  ip  ip  ip  ip  ip  ip  ip  ip  1C  1C 

CCCOOSCO<NGOlCi-IGO"*i-Ht^'*    COCO    CO(NOOlCr-tOO'*rH 
-HC5COOOCOt^(Nt>>r-*COi-HlCOlCO5-*iC!COaO<Mr^(NCOr-(CO 
oj      -fOOCOt-fNCOi-HlOO^CS'"' 
1C  1C  1C  CO  CO  I-  t-  00  00  O5  OS  OS 

1C  1C  ip  1C  1C  1C  ip  1C  1C  1C  1C  1C  1C  1C  1C  ip  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C 

ip  ip  ip  ip  ip  1C  ip  1C  1C  10  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  ip  1C  >C  1C  1C  ip 

COCOOSCOC<lOOiOi— (OO-^i— It--*         COCO 

i0" 

1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  CO  CO  CO  CO  CO 
1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  IO  1C  ip  1C  1C  1C  1C  1C  1C  1C  1C  1C 

1C  ip  ip  1C  ip  ip  1C  1C  ip  1C  ip  1C  1C  1C  ip  ip  S  ip  ip  S  ip  ip  ip  S  ip  ip  S  ip 

COCO    CO<MOOiCrHOO->*Hi-lO>'* 

1C  1C  1C  1C  1C  ip  ip  1C  1C  1C  1C  1C  ip  1C  ip  ip  1C  1C  ip  1C  1C  1C  ip  1C  1C  1C  ip  »C 

i— tOO-^i— (t^-^l    COCO    COC<IOOlCi— ICO-^i— iO>-^ 
~  O5  ••*<  O5  CO  " 

ip  1C  1C  ip  1C  1C  1C  1C  ip  1C  ip  ip  1C  »p  1C  1C  ip  1C  1C  1C  ip  1C  1C  1C  ip  ip  1C  1C 

COCOO5CO<NOOiOrHOO*<j!-ll>-*l         COCO         CO(MOO»Ci-(00-*i-HO»-* 

ip  1C  1C  ip  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C 

•^Ir-lt^-^          COCO          CO<MOOlCi-HCO-**li— I  OS  ^ 
COi— llCOlCO-^OSCOOOC^t-C^COi— (COOlC 

_.  oo  as  oj  os  os 
•*  •*  -^  "* 

COCOOSCOC^COlCr— ICO-^i— ll>-^*l          COCO 

t1*  l>-  OO  OO  GO  OO  OO  OO  66  GO  OO  OO  CO  OO  OO  GO  OO  GO 

COCOCSCO<NOOlO.-ICO-*!-lt~"tt<          COCO          CO<MGOlC>-IOO-*l!-lOS'<tl 
-+HO5COOOCOt^<Nt^t-HCOi-HlCOlCOJT^O>COCOC<It~C<JCOi-HCOOlC 
iCOSCOXlNt—  i— ICOOiOCS-»tiOOCOt~!— ICOQlCOJ-^OOCO^-dCppH 

COCOOJCOWOOlOi— (OOT^i— (t~-*i         COCO          _- 

-*O5COOOCOt-(?^t^^HCOi-HlCOlCO5^OiCOOO<Mt~<NCOi— ICOOlC 
•^QOCOt-C^COr- (lCO-t*C5COGO<MCOrHlCO'*OJCOOO<Mt>-f— ICOO 

'fe      g    1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  1C  O  1C  1C  1C  1C  1C  1C  1C  CO  CO  CO  CO  CO 

J 


DECIMALS   OF   1    TON. 


53 


rHOO^i-Ht^-*!          CO  CO 


s 


CO  CC  CO  CO  CO  CO  ^  "*+< 


i— l(?l(MCOCO'^l-^llplOlOCpCOl--t»OOQOOS 

•^   TfH   ^H   -^  ^   ^H   ^ 
t>  t-  b»  t»  !>• 


10  i— i  co  M<  i— i  os  •**< 
I-H  co  o  10 

t-  ,-H  CO  O 


COCOOSCO(MQOiOi-lOO^i-lt>"*          COCO          COlMOOlOrHCO^i-lOS-*! 
•^OSCOCOCOt^fNt^r-ICOr-liCOiOOSitlOSCOCOC^t-CNlCOi— ICOOlO 

§OrHi-HC<|IMCOCO'^l'^l'^llOlCCOCOl>-b-OOGOOOOSO5OOi— li— I 
0000000000000000- 


cococococococococccocococococococo 


cccococococococococo 


COCO 
OCS^ 


COCOCOCOCOCOCOiOCOCOCOCCCOCCCOCOCOCOCOCO 


OOQOOOOOOOQOOOOO 
COCOCOCOCOCOCCCO 


CO  CO  CO  CO  CO  CO  CO  to  CO  CO  CO  CO  CO  CC  CO  CO  t^-  IT—  lr—  l>*  t~—  l>-  l>-  l>-  t>»  l>-  l>» 

CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO 


^COCOb-< 

OOi—  ii—  ii 
10  m  io  ic  m  10  10  i^  »c  o  1 

COCOCOCOCOCOCOCOCOCOC 


COCO          CO<MOO»Oi—  I 
5CO 
OO 

—  ao 


i— I  CO  O  1C 

S^H  1-H  (M 
CO  CO  CO 

cocococococococococococococc 


COCOOSCOCOQOiCi—  IOO-*i—  l 


COOOCOt-(N 
OO<Mt~!-ICO 


t-(Nl--r-HCOi—  liC 


COCO 
Tt(O5 


cccococpcocpcococpcpcpcp 


CO 
COi 


cpcpcpcpcpcpcpcpcpcpcpcpcpcpcocp 


COCO          COC<JGClOrHGO"*i-lOS-* 


•^GOCOt^COCO"—  (lOO^d 
lOtOiCCOCOt-t-GOCXJOSOSOJ 
<N(MC^<M(M(M(M(M(MO-'JiM(M 

cocccocococococococococo 


OOi-Hi-HC^lMCOCOCO-r-HiOOCOCOt- 
COCOCOCOCOCOCOCOCOCOCOCOCOCOCOCO 

cocococococccococccccocococococo 


COCOCiCCfMODiO— »  QO  -*  — It H          COCO 


7C 


COCOCOCOCOCOCOCOCOCOCOC 


<N  t>-  <M  CO  i— I  CO  O  1C 

cpcpcpcpcpcpcpcpcccpcccpcpcpcpcp 


CO<NOOiCr— ICO^'— I  OS  -+l 
<M  CO  i— I  CO  O  1C 
'— ICOO 


GAS  ENGINEER'S  POCKET-BOOK. 


COCOClCC<MGClSrHOO'*r-lt>-*l          COCO          CO<MGOlOr-HGO"<*i-lOS~f 

^Sso^co^Mi-rHco^ino^cs^cscoopwt-^corHcoois 
o 

^^^'^^^^^^^^^SxXXGpGpQOGpGOCOOTGCOOGOOOCO 

i"  <i!c  cc  o  r3  ^  tr  v£  -3  t5  t3  tc  -^  cc  cc  cc  cc  t^  t^  r  ~  r~  r^  r^  i^  t^  i^  S-  r~ 
ttGp&<&Gp&cp<p&Gp<&tt<&&&&&cpcp&<f>(B<p<toiip<g)tcec 

cccoa>co<Moois.-i 

•He f_ 

s  is  in  in  is  in  in  in  in  is  m  in  in  in  is  is  cc  co  co  co  cc 

-^   in  Ci  co  GO  c^  i^»  I-H  co  o  in  os  ^f  co  co  i^-  »^  co  o 

COCOCOCOCOCC^-^-tlTt<-^4^-rH-ti--f-tl-tl-tH-^(-«tl-^-^l-^ 
^<&<&Cp<&CpGpCGCC<&ttCQCp<X<KCGCCCCttttCGttCCCG<&tt(Ktt 

°*      isiniscocot^t^GcoociCiOiOOi-i^Hwdi 

^^Gp<XGpGO!XXCOGOGpGCCOCOXXGO^COGp^^X»»«« 
COCOCiCOINGOinr-IQO^r-lt^-*         COCO         CC^-.v^.x.  r-n^-^^w.  -r 

-^oscococot^crqt-i-Hcor-iinoinoi^CicoGC'Mr^cMcor^coois 

i— li— (i— IrHr— (i— IrHrHi— (i— IrHi— (i— Ii-Hi— li— li— I<NC<IC<I<N<NC<1<N<NC^<N<M 
C»C»GpOpGpGpGpGpGpGpGpGpOOGOGOCpOO<»QOGOOOOOGOGOCOGOCO(X 

CO  CO 

O  ri  <n  ^^  -^  ^  csj  _  _ 

^  O  O  O  O  O  O  O  O  O  O  O  O  O  O  O  O  O  r— I  I-H  r-H  i-^  r— 
OO  OO  GO  GO  GO  GO  GO  GO  OO  GO  OO  OO  GO  GO  GO  OO  OO  OO  OO  OO  GO  GO  GO  OO  GO  GO  OO  Or 

CO 

t>  fi 

cocooicoc^aoini— <x-+i!-Ht>--ti       coco       coc^coini— 100^1— i 

-<t(C5COGOCOl>-<Mt^r- (COi— llSOinO-^CirOOOC^t^-lMCOr-HCO 

01 

<T~  l^.  hi  fl  f^  fi  ti  fi 

IQ '__ 

cpcooicpc<iaoinT— 100-^'— tt^-rjH    .coco 

*inmcococot-t^o6 -- -.,....-    . 

^O  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  t*-  IT—  t>-  t~*  t^-  t~^  ^^  t>-  t*»  t>- 

cococ>cc(Mooini— loo-^i— it^-ti       coco       coc<iooin>— 'oc'fi-HCi-* 

o  o  23  I-H  ^  <M  co  co  -f  -f  ^  is  i's  cc  cc  1^  »^  ac  cc  5: .o-I  c^  o  o  —i  r-i  ?! 
m  m  m  m  m  m  m  is  is  i-  is  is  is  m  is  us  is  is  us  is  is  is  cc  co  co  co  cc 

O      ' 

"I 


DfiCiMAtS    OF    1    TON. 


55 


GOCOt~rH«OOlCG5-*aOCOt~C<JtOi— I  1C 
GSJ  CO  CO  ^  ^  1C  1C  1C  to  to  l>-  t"—  GO  GO  G^  Gi 

OOGOQOGOOOQOGSGJGJGJGSGJGJGSGSGiGJGJGSGSGiGiGSGJGSGiGiGi 

GSG5G>GJGJGSG5G5GiG5G5G5G5GJGSGSG5G5G5G5GiG5GiGSGSG5G5GJ 


GJ  Gd  Gd  Gd  Gd  Gd  G)  Gi  G)  G}  G)  —  -  G»  —  -  -  •  — « 


aOQOOO 

—  -  Gd  _. 


G)  —  .  G^  —  .  G) 


«OCCGJ5CS<ICX)iCi—  ICO^i—  lt>-'*' 


O 

Gs 


mOiCCOOfMt^r-HtCOinGl^GOCOt^i-HCOOiCGJ^QOCOt^lMySrHlO 

t»  t»  co  co  o»  o»  o  o  1-1  i-t  fH  e<j  eq  e  «      •«*  10  »o  »o  eo  «o  t-  1-.  oo  oo  o»  en 


CO  CO  CO  CO  CO  CO 


GJGJOiGiGJGJGiGiGiGSGlGiGSGSGiGSGiG; 


?. 


<*«  O»  CO  CO  CO  fc» 

GSCOOO 


l^  (M  «O  i—  I  CO  O 


i— itOi— liCOiCGS-^GiCO 

GOQOGSGJOOOi-Hi-HCqC^COCO-^-1* 
-(MC<1(^<MC^C^(M(M 

--  _.   -.   ^"-  ^ .   _.  —  -  O^ 


«CCOG5?O(MGOinT-IOO-*'-ll>"* 


o  o  o  o 

C5  O^  Ci  C5  GT5 


tOCO 
^GS-^ 


CCOlGOiOi— (GC^i-HO^^ 

t**  QO  OO  OO  O$  Gi  O  O  f^  rH  C^ 

OOOOOOi-H^Hi-Hi-Hi— f 

O  O)  O«  O  C*  O  G^  C"i  C".  G)  Ci 


GAS  ENGINEER'S  POCKET-BOOK. 

Equivalent  Weights. 

Metric.  English. 

1  milligramme      =      -0154  grain. 
1  centigramme      =      -1543      „ 
1  decigramme        —    1-5432      „ 
1  gramme  =  15-4323      „ 

1  decagramme       =      -3527  oz. 
1  hectogramme      =    3*52/4  „ 
1  kilogramme         =    2-20462125  Ibs. 
1  millier  or  tonne  =  19-6841  cwts. 


English. 

Metric. 

1  grain      = 
1  drachm  = 

•0648  gramme. 
1-7718        „ 

1  oz.          = 

28-3495 

1  Ib.          = 

•4535926  kilogramme. 

1  stone     = 

6-3503                „ 

1  quarter  = 

12-7006 

1  cwt.        •= 

50-8024    •            „ 

1fr\n                  I 

1016-048 

l/OIl              —  -     -s 

1-01605  metric  tonne. 

Equivalent  Liquid  Measures. 

Metric.  English. 

1  centilitre  |                           . 

10  cubic  centimetres  |"  —        U17b  Pmt 

1  decilitre  =       -1761     „ 

1  litre  =        -2201  gallon. 

1  decalitre  =     2-2009      „ 

1  hectolitre  =    22-009        „ 

1  cubic  metre  =  220-09          „ 

English.  Metric. 
1  gill  or  quartern  =    -1420  litre. 

1  pint  =    "5679     „ 

1  quart  =  1-1359     „ 

1  gallon  =  4-5435     „ 


Equivalent  Measures  of  Length. 

Metric. 

English. 

millimetre  = 

•03937  inches. 

centimetre  = 

•3937        „ 

decimetre    = 

3-93704      „ 

metre          =  \ 

39-3704         „ 
3-2809  feet. 

decametre  = 

32-8087     ,. 

hectometre  = 

109-3623  yards. 

( 

3J80-369  feet. 

1  kilometre    =  < 

1093-623  yards. 

( 

•62138  mile. 

EQUIVALENT   MEASURES   OF   LENGTH. 


57 


English. 
linch 
1  link 
1  foot 
1  yard 
1  fathom 

1  rod,  pole  or  perch 
1  chain 

1  furlong 

Imile 

1  admiralty  knot 
or  nautical  mile 


Metric. 

25'4  millimetres. 
•2012  metre. 
•3048       „ 
•91439 
1-82878 
5-02915 
20-11662 
201-1662 

0-20117  kilometre. 
1609-3296  metres. 

1-6093296  kilometres. 

1-85315 


Pounds 


Square  inches 
Circular  inches 
Cylindrical  inches 
Cubic  inches 

»>         » 

„     feet 
Cylindrical  inches 

„          feet 
Cubic  inches 


Cylindrical  inches 


•00893  =  cwts. 

•00045  =  tons. 

•007  =  square  feet. 

•00546  =       „ 

•0004546  =  cubic  feet. 

•00058  =      „       „ 

•003607  =  imperial  gallons. 


=  Ibs.  avoirdupois  of  wrought  iron. 
„  steel. 
„  copper. 
„  brass. 


X 

X 

X 

X 

X 

X 

X 

X  6-232          = 

X     '002832 

X  4-895 

X     '281 

•283 

•3225 

•no:?  7 

•26 

•4103 

•2636 

•4908 

•2168 

•2223 

•2533 

•2385 

•2042 

•3223 

•207 

•3854 


zinc. 

lead. 

tin. 

mercury. 

wrought  iron. 

steel. 

copper. 

brass. 

zinc. 

lead. 

tin. 

mercury. 

Metric  Equivalents. 

To  convert  grains  into  grammes 

grammes  into  grains 

drachms  into  grammes 

ounces  (avoirdupois)  into  grammes 

pounds  „  „          „ 

cubic  centimetres  into  grains 
„  „  „    drachms 

,,  „  .,    ounces  (avoirdupois) 

pints  into  cubic  centimetres 

litres  into  ounces  (avoirdupois) 

gallons  into  litres 


0-065 
15-5 
3-9 
28-4 
453-6 
15-5 
0-29 
0-036 
X  473 
X    35-5 
X      3-8 


58 


GAS  ENGINEER'S  POUKET-BOOK. 


To  Convert  Grammes,   Decigrammes,   Centigrammes  and 
Milligrammes  to  Grains. 


1  gramme  =  15 '4323  grains. 

2  „        =  30-8646      ., 

3  v        =46-2969      „ 

4  .,        =  61-7292      „ 

5  =  77-1615 


6  grammes  =    92-5938  grains. 

7  .,         =  108-0261       ., 

8  „         =  123-4584       ., 

9  =  138-8907 


For  the  number  of  grains  in  a  decigramme  shift  the  decimal  point 
one  place  to  the  left,  thus,  1  decigramme  =  1-54323  grains. 

For  the  number  of  grains  in  a  centigramme  shift  the  decimal  point 
two  places  to  the  left,  thus,  1  centigramme  =  -154323  grains. 

For  the  number  of  grains  in  a  milligramme  shift  the  decimal  point 
three  places  to  the  left,  thus,  1  milligramme  =  -0154323  grains. 

Cubic  Feet  into  Cubic  Metres. 


Cubic 
feet. 

Cubic 
metres. 

Cubic 
feet. 

Cubic 
metres. 

Cubic 
feet. 

Cubic 
metres. 

Cubic 
feet. 

Cubic 
metres. 

1 

•0283 

31 

•8778 

61 

1-7272 

91 

2-5767 

2 

•056!) 

32 

•9061 

62 

1-7555 

92 

2-6050 

3 

•0849 

33 

•9344 

63 

1-7838 

93 

2-6333 

4 

•1133 

34 

•9627 

64 

1-8122 

94 

2-6616 

5 

•1416 

35 

•9910 

65 

1-8405 

95 

2-6899 

6 

•1699 

36 

1-0193 

66     '  1-8688 

96 

2-7182 

7 

•1982 

37 

1-0477 

67     ,  1-8971 

97 

2-7466 

8 

•2265 

38 

1-0760 

68        1-9254 

98 

2-7749 

9 

•2548 

39 

1-1043 

69        1-9537 

99 

2-8032 

10 

•2831 

40 

1-1326 

70 

1-9820 

100 

2-8315 

11 

•3115 

41 

1-1609 

71 

2-0104 

200 

5-663 

12 

•3398 

42 

1-1892 

72 

2-0387 

300 

8-494 

13 

•3<>S1 

43 

1-2175 

73 

2-0670 

400 

11-326 

14 

•3%4 

44 

1-2459 

74 

2-0953 

500 

14-157 

15 

•4247 

45 

1-2742 

75 

2-1236 

600 

16-989 

16 

•4.~>30 

46 

1-3025 

76 

2-1519 

700 

19-820 

17 

•4814 

47 

1-3308 

77 

2-1803 

800 

22-652 

18 

•5097 

48 

1-3591 

78 

2-2086 

900 

25-483 

19 

•5380 

49 

1-3874 

79 

2-2369 

1.000 

28-315 

20 

•5663 

50 

1-4157 

80 

2-2652 

1,500 

42-472 

21 

•5946 

51 

1-4450 

81 

2-2935 

2.000 

56-620 

22 

•6229 

52 

1-4724 

82 

2-3218 

2500 

70-787 

23 

•6512 

53 

1-5007 

83 

2-3501 

3000 

84-944 

24 

•6795 

54 

1-5290 

84 

2-3785 

4000 

113-240 

25 

•7079 

55 

1-5573 

85 

2-4068 

5000 

141-574 

26 

•7362 

56 

1-5856 

86 

2-4351 

6000 

169-888 

27 

•7645 

57 

1-6140 

87 

2-4634 

7.000 

198-184 

28 

•7928 

58 

1-6423 

88 

2-4917 

8000 

226-480 

29 

•8211 

59 

1-0701; 

89        2-5200 

9  000       254-814 

30 

•8494 

60 

1-6989 

90       2-5483 

10.000    j  283-148 

OUBIO  METRES   INTO   CUBIC   FEET.  5-9 

Cubic  Metres  into  Cubic  Feet. 


Cubic 

Cubic 

Cubic 

Cubic 

Cubic 

Cubic 

Cubic  I   Cubic 

metres 

feet. 

netres 

feet 

metres 

feet. 

metres    feet. 

1    35-3156 

31 

1094-7836 

61 

2154-2516 

91 

3213-7196 

2 

70-6312 

32 

1130-0992 

62 

2189-5672 

92 

3249-0352 

3 

105-9468 

33 

1165-4148 

63 

2224-8828 

93 

3284-3508 

4 

141-2624 

34 

1200-7304 

64 

2260-1984 

94  3319-r><>64 

5 

176-5T80 

35 

1236-0460 

65 

2295-5140 

95 

3354-9820 

6 

211-8936 

36 

1271-3616 

66 

2330-8296 

96 

3390-2976 

7 

247-2092 

37 

1306-6772 

67 

2366-1452 

97 

3425-6132 

8 

282-5248 

38 

1341-9928 

68 

2401-4608 

98 

3460-9288 

9 

317-8404 

39 

1377-3084 

69 

2436-7764 

99 

3496-2444 

10 

353-1560 

40 

1412-6240 

70 

2472-0920 

100 

3531-560 

11 

388-4716 

41 

1447-9396 

71 

2507-4076 

110 

3884-716 

12 

423-7872 

42 

1483-2552 

72 

2542-7232 

120 

4237-872 

13 

459-1028 

43 

1518-5708 

73 

2578-0388 

130 

4591-028 

14 

494-4184 

44 

1533-8864 

74 

2613-3544 

140 

4944-184 

15 

529-7340 

45 

1589-2020 

75 

2648-6700 

150 

5297-340 

16 

565-0496 

46 

1624-5176 

76 

2683-9856 

160  5650-496 

17 

600-3652 

47 

1659-8332 

77 

2719-3012 

170  6003-652 

18 

635-6808 

48  1695-1488 

78 

2754-6168 

180  (1356-808 

19 

670-9964 

49  '  1730-4644 

79 

2789-9324 

190  (1  709-964 

20 

706-3120 

50 

1765-7800 

80 

2825-2480 

200   7063-120 

21 

741-6276 

51 

1801-0956 

81 

2860-5636 

250  8828-900 

22 

776-9432 

52 

183(5-4112 

82 

2895-8792 

300  10594-468 

23 

812-2588 

53 

1871-7268 

83 

2931-1948 

350  12363-46 

24 

847-5744 

54 

1907-0424 

84 

2966-5104 

400  ;14126-24 

25 

882-8900 

55 

1942-3580 

85 

3001-8260 

500 

1  7657-80 

26 

918-2056 

56 

1977-6736 

86 

3037-1416 

600 

21189-36 

27 

953-5212 

57 

2012-9892 

87 

3072-4572 

700 

24720-92 

28 

988-8368 

58 

2048-3048 

88 

3107-7728 

800 

28252-48 

29 

1024-1524 

59 

2083-6204 

89 

3143-0884 

900 

31784-04 

30 

1059-4680 

60 

2118-9360 

90 

3178-4040 

1000 

38847-16 

Demy  . 
Medium 
Royal  . 
Imperial 
Elephant 


Sires  of  Drawing  Paper. 


20  X  15 
22  X  17 
24  X  19 
31  X  21 
27  X  23 

Columbier     . 
Atlas     . 
Double  Elephant  . 
Antiquarian  . 
Emperor 

.    34  x  23 
.    33  X  26 
.     40  X  26 
.     52  X  29 
.     68  X  48 

60 


GAS  ENGINEER'S  POCKET-BOOK. 


Colours  used  in  Architectural  and  Engineering  Drawings. 

For  Brickwork  in  plan  or  section 


(to  be  executed) 
Brickwork  in  elevation. 

Flintwork  or  parts  of  brick- 
work to  be  removed 

Granite         . 

Cement  or  Stone  . 

Concrete       . 

Clay  Earth  . 

Plaster          . 

Slate     

Tiles     .... 

Wood 

English  Timber,  not  Oak     . 

Oak  or  Teak 

Fir  Timber  . 

Mahogany    . 

Iron,  wrought 
„    cast      . 

Lead 

Copper 

Brass 

Gunmetal    .. 

Glass 

Leather         . 

Meadow  land 

Sky  effects   . 


Crimson  Lake  or  Carmine. 
Venetian  red  or  Crimson  Lake 
and  Burnt  Sienna  (light). 

Prussian  Blue. 
Violet  Carmine. 
Sepia. 

„    mottled  with  Burnt  Umber. 
Burnt  Umber. 
Sepia  (light). 

Indigo  with  Crimson  Lake. 
Indian  red. 
Burnt  Sienna. 
Raw 

Burnt      „ 
Indian  yellow. 

„       red. 
Prussian  blue. 
Payne's  Grey. 
Indigo  or  light  Indian-ink. 
Crimson  Lake  with  Gamboge. 
Gamboge. 
Dark  Cadmiums. 
Cobalt  mottled. 
Vandyke  brown. 
Hooker's  Green. 
Cobalt  Blue. 


Weight  of  Materials. 


MATES  LAJLS. 

Weight  of  One 
Cubic  Foot. 

Cubic  Feet 
per  Ton. 

Ibs. 

37 

60A 

„      52  feet  =  1  chaldron    .         .     . 

""2 

Brickwork    

100 

22| 

„         in  cement       .        .        .     . 

110 

20§ 

Bricks,  red  kiln  

135 

17 

„      common      

110 

20f 

„       London  Stock  .... 

115 

19| 

„      Welch  fire  

150 

15 

Cement,  Portland        .... 

84 

26$ 

„               „        cask  4  bushels  =     . 

5  feet 

2  cwt. 

„        Roman  

60 

37* 

„             „       cask  5  bushels  =  .     . 

6  feet 

4  cwt. 

Chalk  

140  to  166 

15£  to  13J 

Clay                  .                 .... 

120  to  135 

18|  to  17 

WEIGHT   OF   MATERIALS. 


61 


MATERIALS. 

Weight  of  One 
Cubic  Foot. 

Cubic  Feet 
per  Ton. 

Ibs. 

Coal,  Cannel  and  Welsh      . 

84 

26f 

„      Newcastle      

80 

28 

Coke     

47 

48 

Concrete  

120 

18} 

Earth  

95  to  126 

23J  to  18 

Flint        

164 

13| 

Glass,  Crown        .         . 

157 

„      Flint      

187 

12* 

„      Plate.        ... 

184 

12i 

Gravel     

112  to  120 

21f  to  18§ 

Iron,  cast     

450 

5 

„     wrought  

487 

4f 

Lime,  stone  

53 

42£ 

„      chalk     

44 

51 

Mortar,  from  (old)       .... 

88 

25^ 

,,       to  (new)     

119 

19 

Sand,  pit      

90 

23^  to  25 

„      river      

118 

19 

Shingle         

.  .. 

... 

Slate        

..  . 

13i 

.,      Purbeck         

... 

133 

„      Yorkshire  
„      Craigleith     

... 

ill 

„      Derby        

... 

15 

„      Portland       

... 

14f 

Bath  

... 

16 

Marble     

12J  to  13 

Tiles,  average       

112 

20 

Oil  of  Turpentine    

54| 

41 

„      Linseed      

58f 

38 

„      Whale    

57| 

39 

Rain  Water  (252  gallons  per  ton) 

35 

Sea      „         (224         „          „       )  .     . 

64 

35 

Gallon  of  water  =  10  Ibs.  =  211  \  cubic  inches. 

6J      „               ,,      =  1  cubic  foot  nearly. 

Roofing  —  1  square  of  100  feet  slating                                  =  10£  cwt. 

„                     „            „            „        and  timbers            =  15§    „ 

tiling                                    =  15*    „ 

„            „            „      and  timbers              =  21      „ 

..                     „            ,.        with  7  Ib.  lead                     =10      „ 

„                      ,,             ,                   „           and  timbers  =  17      „ 

,        with  6  Ib.  lead                     =    8£    „ 

„                      „             ,                    „            and  timbers  =  15£     „ 

„                      „             »        with  16  gauge  zinc              =    3£     „ 

„          1          .,             ,                   „           and  timbers  =  10J    „ 

62  GAS  ENGINEER'S  pocKET-BooKr 

Miscellaneous  Articles. 
One  barrel  of  tar        =  2G£  gallons. 
Battens  =  boards  7  inches  wide. 

Bushel  of  coal  =  80  Ibs. 

„        coke  =  45    „ 

„         quicklime  =  70    „ 
Chaldron  of  coal         =  25£  cwts. 

„          coke        =  12i  to  15  cwts. 
Fodder  of  lead  =  19J  cwts. 

Hundred  of  deals       =  120  in  number. 

nails        =120          „ 
Load  of  bricks  =  500          „ 

„       lime  (1  ton)  =  32  bushels. 
„       sand  =  36         „ 

Planks  =  boards  12  inches  wide. 

Sack  of  coal  =  224  Ibs. 

Square  of  planking    =  100  superficial  feet. 
slate  =100 


Weight  of  Ear 

Cwt. 
1  cub.  yd.  sand      .     .  =  30 
1         ,'    gravel        .  =  30 
1         ,      mud       .    .  =  25 
1          ,      marl  .        .  =  26 
1          ,      clay   .        .  =  31 
1          ,      chalk     .     .'=  35  to  36 
1         „      cannel  coal  =  81  to  87 

ths,  Rocks,  etc. 

1  cub.  yd.  sandstone 
1        „      shale      . 
1         .,       quartz 
1         .,      granite  . 
1         .,      trap   . 
1        „      slate      . 

Cwt. 
.  =  39 
.  =  40 
.  =  41 
.  =  42 
.  =  42 
.  =  43 

Natural  Slopes  of  Earths  with  the  Horizontal  or  Angles  of  Eepose. 


Gravel,  average 

.  40° 

„       and  sand  mixed 

.  38° 

Dry  sand 

.  37°  to 

38°  =  1-33    to  1 

Sand   .... 

.  21°  to 

22°  =    -263  to  1 

„    fine  dry 

.  32° 

Vegetable  earth  or  peat 

.  28° 

=  1-89    to  1 

„            „     new       . 

.  34° 

Compact       „ 

.  48°  to 

50°  =    -09    to  1 

Loamy          „ 

.  40° 

=  1-2      to  1 

Shingle,  average 

.  39°  to 

40°  =  1-2      to  1 

„        clean. 

.  36° 

Rubble,  average  . 

.  45° 

=  1  to  1 

Clay,  well  dried      . 

.  45° 

=  1  tol 

„     stiff  or  dry  mud 

.  45° 

as  1  to  1 

„     wet,  average 

.  16° 

.,        „    London 

.  15° 

Coal 

33° 

=  1-66  to  1 

1  cub.  yd.  rock  in  large  pieces   =  when  excavated  1*50  c.  yds. 

1        „  „       medium  as  dug  =      ..  „         1  -25  to  1-30  c.  yds. 

1        „        chalk     .        .        .     .  =      „  „         1-30  c.  yds. 

1        ..        sand  and  gravel         .  =      ,,  „         1*07      „ 

1        „        clay  and  earth      .     .  =      ..  „          1-2  to  1-25  c.  yds. 


RESULTS   OF   POWER. 

Observed  Eesults  of  Power  (Nystrom). 


63 


Work 

Effects 

Description  of  Works. 

hours 
per 

Force. 

Velocity 

of  ft. 
Ibs.  per 

Horses. 

day. 

second. 

A  man  can  raise  a  weight  by  a 

single  fixed  pulley  .     . 

6 

50 

0-8 

40 

0-072 

.,     working  a  crank 

8 

20 

2-5 

50 

0-090 

„    onatreadwheel(horizontal) 
„    in  a  tread  wheel  (axis  24° 

.8 

144 

0-5 

72 

0-130 

from  vertical)    .         .     . 

8 

30 

2-3 

69 

0-125 

„     draws  or  pushes  in  a  hori- 

zontal direction 

8 

30 

2-0 

60 

0-109 

„     pulls  up  or  down    .         .     . 

8 

12 

3-7 

44-4 

0-080 

„     can  bear  on  his  back  . 

7 

95 

2-5 

237-5 

A  horse  in  a  horsemill,  walking 

moderately 

8 

106 

3-0 

318 

0-577 

„           „           „      running  fast 

5 

72 

9 

648 

1-178 

An   ox   in  a   horsemill   walking 

moderately 

8 

154 

2 

308 

0-518 

A  mule        „            „            „ 

8 

71 

3 

293 

0-308 

An  ass         „            „            „ 

8 

33 

2-65 

87-4 

0-160 

On  bad  foot  roads  like  those  in 

Peru  a  man  can  bear    .         .     . 

10 

50 

3-5 

175 

Llama  of  Peru  can  bear 

10 

100. 

3-5 

350 

Donkey  can  bear      .                 .     . 

10 

200 

3-5 

700 

Mule  can  bear 

10       400 

5-0 

2000 

Man  Power. 

Efforts  exerted  for  short  periods  of  time.     R.A.  rule. 

Pushing  a  load  horizontally          ....  100  Ibs. 

Pulling        „  „  70    „ 

Tractive  force  in  dragging  a  cart          .         .         .     40    „ 
Lifting  a  weight  from  the  ground  by  the  hands  .150    „ 

Carrying  on  his  shoulders 120    „ 

On  a  winch  for  continuous  work  .         .         .         .15  to  20  Ibs. 

When  a  number  of  men  are  pulling  on  a  rope,  the  effort  per  man 
will  average  very  much  below  the  above  quotation,  and  the  greater 
the  number  the  less  the  average  per  man.  24  men  will  not  pull  half 
as  much  again  as  12  men.  The  most  advantageous  application  of  a 
man's  power  in  hauling  is  in  a  slanting  direction  downwards,  as  his 
weight  is  added  to  his  strength. 

Power  of  Horses. 

Rate  (miles  per  hour)  =2       3      3£    4    4J    5 
Tractive  force  in  Ibs.    =  166  125  104  83  62  41 


64 


GAS  ENGINEER'S  POCKET-BOOK. 


To  set  out  a  perpendicular  measure  a  base  of  4  parts,  perpendicular 
measuring  3  parts  and  diagonal  5  parts. 


To  Divide  a  given  Line  into  any  number  of  Equal  Farts. 


Let  A  B  be  the  line  to  be  divided,  then  at  B  erect  perpendicular 
B  C,  then  on  the  line  A  C  set  out  the  divisions  by  any  convenient 
scale,  and  from  the  points  as  D  E  F  draw  lines  perpendicular  to  A  B, 
which  will  cut  at  G  H  K  the  divisions  required. 

This  method  is  useful  for  making  scales  to  uneven  dimensions. 

Excavating.— A  man  can  dig  from  5  cubic  yards  in  hard  gravel  to 
10  cubic  yards  in  loose  ground  per  day. 

1  ton  of  light  soil  =18  cubic  feet. 

Carts  usually  hold  2£  tons  or  45  cubic  feet. 

Piles  driven  until  they  are  in  firm  ground  will  stand  1000  Ibs.  per 
sq.  inch  of  area  of  head,  but  when  depending  only  upon  the  friction 
of  their  sides  200  Ibs.  per  square  inch. 

On  sloping  ground  step  and  stair  the  foundations. 

A  cubic  yard  of  earth,  before  digging,  will  occupy  about  1^  cubic 
yard  when  dug. 

A  dobbin  cart  will  contain    f  cube  yard. 

Earth  waggon,  small  size.  H    „       „ 
u  »        large        ,  3      „       „ 

Wheelbarrow    .         .        .    ^    „       „ 
A  single  load  of  earth  =  27  cubic  feet  =  21  bushels. 
A  double      „        „      =  54     „        „ 
1  cubic  yard  of  gravel  =18  bushels  in  the  pit. 
1      „        „  „     =  24       „       when  dug. 

When  formed  into  embankments  gravel  sinks  nearly  \  in  height 
and  decreases  \  in  bulk. 

If  earth  is  well  drained,  it  will  stand  in  embankments  about  \\  to  1. 

Foundations. — 6  of  good  aggregate  to  1  of  ground  lias  lime  will 
answer  every  purpose  in  ordinary  cases,  and  should  be  about  a  foot 
wider  than  the  bottom  course  of  footings,  or  6  inches  on  each  side. 


SAFE    PRESSURES    ON    FOUNDATIONS.  65 

Whenever  large  weights  occur,  as  on  foundations  of  columns, 
angles  of  buildings,  &c.,  Portland  cement  should  be  used  in  place 
of  lias  lime  ;  the  dimensions  can  be  increased  if  desirable. 

Foundations  in  water  are  formed  sometimes  by  rows  of  wooden 
piles  so  fastened  together  as  to  form  a  pier  for  the  horizontal  beams 
to  be  fixed  upon,  as  in  wooden  bridges.  A  great  objection  to  wooden 
piles  is  the  fact  that  in  water,  fluctuating  by  the  tide,  the  timber 
decays  at  the  water-line  and  therefore  requires  to  be  sheathed  with 
copper. 

The  following-  Pressures  may  be  used  with  safety  pei-  superficial 
foot  for  Foundations  : — 

Tons. 
Rock.         .         .         .         .         .         .         .13 

Chalk 4 

Solid  blue  clay  and  gravel        .        .  3  to  6 

London  clay 2 

12  in.  by  12  in.  piles  well  driven       .         .     20  to  30 
Well  punned  ground  will  sustain  1  ton  per  square  foot,  if  punned 
each  foot  as  filled  in  ;  if  not,  not  more  than  ^  ton  per  square  foot. 
Gravel,  good  in  foundation  will  uphold  5  tons  per  square  foot. 
Sandy  gravel,  near  water,  1£  tons  per  square  foot. 
Foundation  always  2  ft.  6  in.  below  ground  line. 

Tons 
per  sq.  ft 
Moist  clay  and  sand  (prevented  from  spreading  laterally)      .     1-36 

Coarse  sand  and  dry  clay 2'27 

Firm  bedded  broken  stones  on  dry  clay 3 '18 

Loose  impermeable  beds  with  piling 1-82 

„  „  „        „         „       and  concrete .         .         .     2*73 

It  is  necessary  at  all  times  to  allow  sufficient  room  for  men  to  work 
in  a  trench  where  it  has  to  be  excavated  more  than  3  feet  deep. 

In  loose  ground  a  man  can  throw  up  about  10  cubic  yards  per  day, 
but  in  hard  or  gravelly  soils  5  yards  will  be  a  fair  day's  work.  Three 
men  will  remove  30  yards  of  earth  a  distance  of  20  yards  in  a  day. 

A  yard  of  concrete  requires  about  3  hours'  labour  to  mix  and  throw 
in,  or,  if  in  heavy  masses  and  the  materials  handy,  about  2  hours. 

Burning  clay  into  ballast  is  done  by  making  a  fire  of  small  coal  or 
coke  breeze,  and  casing  the  same  with  clay,  laying  alternate  layers 
of  fuel  and  clay  until  the  mass  is  burnt  through.  2  tons  of  small 
coals  will  burn  about  25  cube  yards  of  earth.  It  is  used  for  roads 
and  concrete  walls,  and  very  frequently  ground  for  mortar  as  a  sub- 
stitute for  sand,  but  it  is  essential  that  when  used  for  such  a  purpose 
it  be  well  burnt.  Value,  reckoning  coals  at  15s.  per  ton,  2*.  Qd.  per 
cubic  yard. 

19  cubic  feet  of  sand.  18  ditto  clay,  24  ditto  earth,  15 £  ditto  chalk 
20  ditto  gravel,  will  each  weigh  1  ton. 

Footings — Projection  at  bottom  on  each  side  should  not  be  less, 
than  half  the  thickness  of  wall  at  base,  diminishing  in  regular  offsets, 
and  height  not  less  than  projectio  \ 

CUE.  V 


66  GAS  ENGINEER'S  POCKET-BOOK. 

Punn  all  trenches  before  putting  in  concrete  for  foundations,  and 
drain  off  all  surface  water  permanently. 

Sewerage  about  5  feet  head  per  mile  is  required  to  maintain  a  flow 
and  to  overcome  friction  in  small  pipes. 

Temperature  increases  about  1°  F.  for  every  60  feet  below  the  level 
of  the  ground. 

Damp  Course. — This  is  to  prevent  the  moisture  rising  in  the  walls, 
and  should  be  placed  from  6  to  12  inches  above  Jhe  ground  line.  It 
can  be  made  of  slates  laid  in  Portland  cement,  but  recently  asphalte 
has  been  adopted  and  is  effective  and  economical.  A  glazed  earthen- 
ware damp  course,  with  ventilating  spaces  through  its  centre,  has  also 
been  suggested. 

Damp  Courses  for  External  Walls  (Prof.  H.  Adams)  : — 

A  course  of  slates  throughout  the  thickness,  3  to  6  inches  above 

ground  line. 

A  double  course  of  slates  in  cement,  3  to  6  ins.  above  ground  line. 
A  layer  of  asphalte,  j  to  ^  inch  thick,     ,,         „         „         „         „ 
A  layer  of  cement,     „         „         „         „         ,,         „         „         ., 
Taylor's  patent  glazed  and   perforated    stoneware    slabs,   above 

ground  line. 
A  layer  of  melted  pitch  with  sufficient  coal-tar  mixed  in  to  prevent 

it  setting  too  brittle. 

A  layer  of  sheet  lead  4  Ib.  to  8  Ib.  per  square  foot,  with  1£  in.  laps 

(the  best). 
A  layer  of  asphalted  (!<?.,  tarred)  roofing  felt  laid  dry. 

Inverted  Arches  should  be  turned  from  pier  to  pier  in  all  heavy 
buildings  to  equalize  the  weight  throughout  the  building  and  thus 
prevent  unequal  settlement.  Arches  are  generally  worked  in  half- 
brick  rings,  thus  saving  a  vast  amount  of  cutting  and  waste,  but  a 
course  of  headers  should  be  thrown  up  every  3  or  4  feet,  the  upper 
course  bonded  over  the  lower,  to  tie  the  rings  together.  If  this  be 
properly  attended  to  there  will  be  no  fear  of  the  rings  separating 
when  the  centres  are  struck. 

Hoop-iron  bond,  usually  1|  in.  x  ^  in.,  should  be  well  tarred  and 
sanded  before  use  and  laid  say  every  5  feet  in  height  of  wall. 

Asphalte  damp  course  usually  £  inch  thick  at  12  inches  above 
ground  line. 

Slate  damp  course,  usually  2  courses  thick,  carefully  bedded  and 
laid  in  floating  cement,  upper  layer  overlapping  the  lower  to  prevent 
cracking  ;  they  should  project  1^  inches  beyond  the  wall  on  each  side. 

A  rise  of  £  inch  per  foot  span  usually  allowed  in  making  centres 
for  flat  arches  for  settlements. 

Wood  slips,  about  f  inch  thick  in  joints  of  brickwork,  better  than 
wood  bricks,  as  they  are  less  liable  to  shrink. 

Bricks  of  6  parts  breeze  to  1  of  cement  will  allow  nails  to  be  driven 
in  and  they  do  not  shrink. 

Brickwork. — The  roughest  and  hardest  of  the  stock  bricks  to  be 
used  should  be  selected  for  the  footings,  and  worked  English  bond 


BRICKWORK. 


67 


as  high  as  where  the  facing  commences  ;  or  if  the  building  is  faced 
with  stone  or  cement,  English  bond  should  be  worked  all  through 
(excepting  9-iuch  walls),  as  it  is  much  stronger  than  Flemish  bond, 
although  not  so  ornamental.  9-inch  walls  should  in  all  cases  be 
worked  Flemish  bond  ;  or,  from  the  unequal  length  of  the  bricks, 
one  side  will  be  very  rough.  Where  red  bricks  or  seconds  are  used 
for  facings,  Flemish  bond  should  be  worked,  and  care  taken  to 
properly  tie  it  in  with  the  backing  ;  although  a  certain  portion  of 
the  headers  may  be  bats,  every  third  should  be  whole  bricks  and 
occasionally  cross  or  diagonal  bond  should  be  worked  in  the  backing 
to  prevent  the  wall  splitting.  In  dry  weather  the  bricks  should  be 
thoroughly  soaked  before  laying  ;  each  course  of  bricks  must  be 
properly  flushed  in  with  the  trowel,  and  grouted  every  four  courses 
to  ensure  stability  in  the  work. 

Bond. — Hoop  iron,  1£  inches  wide,  is  now  very  generally  used  and 
with  great  advantage.  There  should  be  a  course  of  hooping  to  each 
half  brick  in  thickness,  well  tarred  and  sanded  every  5  feet  in  height, 
and  well  lapped  at  all  angles  ;  the  course  of  bricks  above  and  below 
the  hooping  should  be  laid  in  cement. 

The  quality  of  bricks  and  tiles  may  be  told  by  the  sound  and  by 
their  appearance  when  broken.  If  they  are  well  burnt  through 
and  when  clapped  together  produce  a  good  clear  ringing  sound,  they 
may  be  considered  good  bricks. 


Size  and  Weight  of  Various  Materials. 


DESCRIPTION. 

Size. 

Weight. 

ft.    in. 

ft    in. 

ft.   in. 

Ibs.  oz. 

Stock  or  place  brick 

0     8f 

0     4| 

0    2£ 

5     0 

Paving  brick    .         .         .     . 

0     9 

0    4J 

0     If 

4     6 

Dutch  Clinker 

0     6J 

0    3 

0     1J 

1     8 

Pantile      

1     if 

0    9£ 

0    0* 

5     0 

Bridgewater  pantile 

1     1* 

1     7 

0    0£ 

9     0 

Plain  tiles         .... 

0  10$ 

0     6i 

0    Of 

2     5 

Pavement  foot  tile 

0  11| 

0  llf 

o    H 

13     0 

10  in.  .     . 

0     9| 

0     9f 

0     1 

8     9 

Pantile  laths,  10  ft.  bundles. 

contains  12  laths         .         '. 

120     0 

o    H 

0     1 

4    6 

Ditto  ;  a  12  ft.  bundle  con- 

tains 12  laths        .         .     . 

144     0 

0     1J 

0     1 

5     0 

Plain    tile    laths,    in    5    ft. 

bundles,  contains  500  laths 

500     0 

0     1 

0    Oi 

3     0 

Thirty  bundles  of  laths  1  load 

... 

•  .« 

... 

cubic. 

A  bricklayer's  hod 

1     4 

0     9 

0     9 

1,296  in. 

A  single  load  of  sand        .     . 

3     0 

3     0 

3     0 

27ft. 

A  double  load  of  sand  . 

3     0 

3     0 

6     0 

54ft. 

A  measure  of  lime    .         .     . 

3     0 

3     0 

3     0 

27ft. 

F    2 


GAS  ENGINEER'S  POCKET-BOOK. 
Fire  Bricks  Weigh  per  1000. 


SIZES. 

Martins. 

Scotts. 

Welsh. 

Tus.  Cts.  Qr.  Lb. 

Tns.  Cts.  Qr.  Lb. 

Tns.  Cts.  Qr.  Lb. 

9  in.  Bricks      . 

2      19     0     0 

3000 

2     17     1     0 

7  in.      „ 

2     11     1     0 

...          ... 

6  in.      „ 

4620 

...         ... 

3  in.      „ 

3     13     2     0 

3     12     10 

3     11     3     7 

Side  Bevels 

2     12     2     0 

2       430 

1     17     3     0 

9  in.  end  do.     . 

2     14     0     0 

2     11     1  21 

...         ... 

7  in.    „      „       . 

1     18     1     0 

2020 

... 

F.  Edge   . 

1     12     1     0 

1     13     1     0 

l"*6     0     0 

Arch    .        .     . 

2     18     1     0 

2730 

2     15     3     0 

Closers     . 

1810 

1     10    3     0 

... 

2  in.  Splits  .     . 

2200 

2     10     2     0 

2800 

l|in.     „ 

1     17     2     0 

1     16     0     0 

1     15     1     0 

lin.       .,      .     . 

1410 

1610          1320 

Resistance  to  Crushing. 

Exposed  Surface,  Average  Crushing 

Square  inches.  Weight,  Tons. 

Oldharn  red  bricks    .         .         .     39'33     ...     40 

Medway  gault  bricks    .         .     .     40'15         .  .     .     17 

„        pressed        .         .         .       —      .  .         .48 

Stafford  blue  brick        .         -     .     27'9        .  .  .     .     50 

Fire-clay  brick .         .         .         .     34-85     .  .         .65 

Wortley  blue  brick       .         .     .    34-76        .  .     .     72 

Portland  stone  ....     39-94     .  .         .47 

Bramley  fall  stone        .         .     .     39'94         .  .     .     91 

Yorkshire  landing     .        .         .     38*28     .  - .        .     96 

Bricks  made  of  neat  cement  9  X  4^  x  2f,  subjected  to  hydraulic 

pressure,  at  the  following  ages  : — 

3  months  old  fractured  by  a  pressure  of  65  tons. 

9       "  "  »  I  »   .120     ',' 

The  pressure  was  applied  in   their  bed,  having  a  superficies  of 
38-25  square  inches. 

Strength  of  Columns  of  brickwork  (height  =  less  than  thickness). 

Crushing 
Commences  at 
Bricks,  hard  stocks,  best  quality,  set  in  Portland  cement 

and  sand  (1  to  1),  3  months  old 40  tons. 

Bricks,  ordinary  well  burnt  London  stocks,  3  months  old  .     30     „ 
„        hard  stocks  Koman  cement  and  sand  (1  to  1),  3 

months  old       .        .         .         .         .     28     „ 
„          „          „       lias  lime  and  sand  (1  to  2),  6  months 

old 24     „ 

„          „          ,,       grey  chalk-lime  and  sand  (1  to  2),  6 

months  old 12  ^  „ 

Herring, 


BRICKWORK.  69 

Brick  and  Stone  Pillars  should  never  be  built  of  a  height  more 
than  12  times  the  thickness  at  base. 

Where  height  =  24  times  thickness  strength  is  reduced  to  •? 

)»  ?>          «"  jj  j?  ?)  )j  >»      " 

„          „      =  40        „  „  „  „  „   -3 

Safe  load  should  equal  ^  breaking  load. 

Hard  red  bricks  have  sp.  gr.  2-136,  and  will  absorb  4-56  %  water. 
Soft      „        „  „        „      1-981,          „          „       8-81  %      „ 

Fire  .,          „        „      2-000,  „  „       5'17  %      „ 

1,000  stock      bricks  weigh  60|  cwts. 

1.000  red  kiln     „  „      63       „ 

liOOO  paving       „          „       45       „ 

The  essential  quality  of  a  brick  is  hardness,  and  that  it  shall  not 
absorb  more  water  than  one-sixth  its  weight.  The  highly  vitrified 
brick  only  absorbs  one-thirteenth  to  one-sixteenth  its  weight. 

The  characteristics  of  a  good  brick  are  :  (1)  it  should  be  free  from 
flaws  ;  (2)  it  should  have  a  good  ring  when  struck  ;  (3)  the  surfaces 
of  the  sides  and  faces  must  be  level,  not  hollow  or  rounded  excepting 
the  ufrog"  ;  (4)  the  surfaces  must  not  be  too  smooth,  or  the  mortar 
will  not  adhere  thereto  ;  (5)  the  brick  must  be  well  burnt ;  and 
(6)  a  brick  should  not  contain  any  white  patches  nor  show  small 
stones  or  rough  particles,  when  broken. 

If  a  brick  be  made  red-hot,  and  when  dropped  into  water  does  not 
break  up,  it  is  of  very  good  quality. 

Bricks,  unless  of  very  bad  quality,  are  not  much  affected  by  the 
solvent  power  of  rainwater  or  the  acids  it  holds  in  solution. 

Analysis  of  a  Brick  Clay  of  Average  Quality. 

Silica 49-44 

Alumina 34-26 

Ferric  Oxide    ....  7'74 

Lime 1-48 

Magnesia 5'14 

Alkalies                                 .     .  — 

Water       ....  1-94 


100-00 

English  bond  consists  of  alternate  courses  of  headers  and 
stretchers. 

Flemish  bond  consists  of  headers  and  stretchers  alternately  in 
every  course. 

Brickwork  in  mortar  weighs  per  cubic  foot,  100  Ibs. 
„          „  cement        „         „          „          110  „ 

1  rod  of  brickwork  requires  1^  cubic  yards  chalk  lime  and  3  yards 
sand  ;  or  1  cubic  yard  stone  lime  and  3£  yards  sand ;  or  36  bushels 
cement  and  36  bushels  sharp  sand. 

4,350  bricks  required  per  rod  reduced  work  if  set  4  courses  1  foot 
high. 

1  rod  of  brickwork  weighs  about  15  tons  and  contains  235  cubic 
feet  bricks  and  71  cubic  feet  mortar. 


70 


GAS    ENGINEERS    POCKET-BOOK. 


ii 


FLEMISH    BOND    CORNERS. 


71 


±f 


^ 


mo 


Hi 


1 

I 

4 

I 

fHK 

[1 

i 

£ 

( 

72  GAS  ENGINEER'S  POCKET-BOOK. 

A  bricklayer  should  lay  1,000  to  1,500  bricks  per  day  in  mortar 
(1  cement  to  3  sand). 

English  bond  gives  the  strongest  building  possible,  and  warehouses 
and  other  buildings  in  which  strength  is  essential  should  be  built  in 
this  style. 

The  rule  for  the  thickness  of  walls  under  the  Metropolitan  Building 
Act  is, 

T_HL 
~N  1) 

Where  T  =  thickness  to  be  found, 
H  =  height  in  feet, 
L  =  length  in  feet, 
N  =»the  constant. 

1)  =  diagonal  of  the  face  of  the  wall. 

The  constant  N  =  22  for  dwelling-houses,  20  for  warehouses,  and 
18  for  public  buildings. 

Brick  on  edge  coping  should  be  set  in  1  Portland  cement  to  2  or  3 
sand. 

1  square  of  pointing  requires  1£  bushels  sand,  \  bushel  lime,  and 
small  per  cent,  of  cement. 

To  Preserve  Scaffold  Cords. — Dip  when  dry  into  a  bath  of  20  grains 
sulphate  of  copper  per  litre  of  water  and  keep  in  soak  for  4  days, 
then  dry.  The  copper  salt  should  then  be  fixed  in  the  fibres  by  a 
coating  of  tar  ;  to  do  this,  pass  the  rope  through  a  bath  of  boiled  tar, 
hot,  drawing  it  through  a  thimble  to  press  back  surplus  tar.  and 
suspend  on  a  staging  to  dry  and  harden. 

Scaffolding. — The  putlogs  or  cross-pieces  are  generally  6  feet  long, 
one  end  bearing  on  the  ledgers  and  the  other  end  resting  in  the  wall  ; 
upon  these  are  placed  the  boards  to  form  the  stage.  In  scaffolding 
great  care  should  be  taken  to  see  it  is  well  braced. 

Resistance  to  tensile  strain  per  square  inch  of  Mortar  in  Brick 

joints  after  setting  for  168  days. 
Common  stock  bricks,  with  masons'  mortar  (1  lime,  2  sand 


\  smithy  ashes) . 
Common  stock  bricks,  with  bricklayers'  mortar  (1  lime 

1  sand,  1  smithy  ashes) 
Firebricks,  with  bricklayers'  mortar 


masons 


27-5  Ibs. 

33-8  ,. 
28-6  .. 
24-0  „ 

Masons'  mortar  loses  about  13  %  on  second  mixing,  and  bricklayers 
28%.—  Bancroft. 

Crushing  load         Crushing  load 
per  sq.  inch.  per  sq.  foot. 

Portland  cement  1  to  1  sand  and  gravel        1*18  tons  170-.")  tons. 

„  „        1  to  3        „  .,  -81     .,  115-5     .. 

„  „        1  to  6         „  „  -03     „  91-0     .. 

Lime  and  sand  lose  one-third  of  their  bulk  when  made  into  mortar. 
Cement  and  sand  „  „  .,  ., 

Sand  in  mortar  prevents  cracking,  and  makes  it  go  farther  ;    also 
permits  air  to  get  to  the  lime  while  setting. 


PORTLAND   CEMENT.  73 

Coarse  is  preferable  to  fine  sand  for  cement  mortar,  up  to  the  size 
that  passes  a  sieve  with  12  and  is  stopped  by  one  with  16  wires  to  the 
inch.  Below  the  grade  of  sand  that  will  pass  40  and  be  stopped  by 
60  wires  to  the  inch  there  is  no  practical  difference  in  the  value  of 
any  sands  so  far  as  the  size  is  concerned. 

The  best  sand  for  mortar  should,  when  magnified,  show  a  sharp 
angular  formation,  not  a  round  or  pisolite  grain  ;  and  as  the  porosity 
of  a  mortar  affects  its  hardening,  especially  in  the  case  of  non- 
hydraulic  limes,  the  size  of  the  grains  should  be  excessively  fine. 

Should  be  as  free  as  possible  from  dirt. 

Good  mortar  will  not  part  easily  when  wet,  or  crumble  under 
finger  when  dry. 

Trap  or  granite  sand,  when  sharp,  appears  to  be  the  best  kind  of 
all  for  the  purpose. 

A  bricklayer's  hod  measures  usually  16"  X  9",  and  =s  1,296  cubic 
inches.  It  will  hold  20  bricks,  or  f  cubic  foot  mortar  (=  nearly  a 
half  bushel). 

Lime,  or  cement  and  sand,  to  make  mortar,  require  as  much  water 
as  is  equal  to  one-third  of  their  bulk,  or  about  5£  barrels  for  a  rod  of 
brickwork  built  with  mortar. 

Directions  for  using  Portland  Cement. 

All  sand,  gravel,  broken  bricks,  or  other  material  used  for  making 
the  concrete,  should  be  clean  and  perfectly  free  from  all  loamy, 
clayey,  or  earthy  substances  whatever,  otherwise  failure  is  sure  to 
result,  notwithstanding  the  undoubted  excellence  of  the  cement. 

Clean  cold  water  should  be  used,  and  only  just  sufficient  to  mix  to 
the  consistency  of  stiff  mortar.  The  water  should  be  added  by  means 
of  a  can  with  a  large  rose,  so  as  to  spread  the  water  evenly  over  the 
materials,  the  materials  being  thoroughly  turned  over  and  mixed 
while  this  is  being  done.  The  use  of  a  bucket  should  be  strictly 
prohibited,  so  as  to  avoid  risk  of  deluging  the  concrete  and 
washing  away  the  cement.  For  stucco  work  only  fresh  water  is  to 
be  used. 

In  order  to  obtain  uniformity  in  the  strength  of  the  work,  it  is 
necessary  that  a  thorough  admixture  of  the  cement  with  the  other 
material  be  made — the  dry  mixture  should  be  turned  over  twice 
before  the  water  is  applied,  and  again  turned  over  twice  in  the 
process  of  wetting.  No  more  cement  should  be  mixed  or  gauged  up 
at  one  time  than  can  be  used  before  the  setting  process  takes  place. 
Cement  that  has  partially  set  and  is  mixed  up  again  will  never 
harden  properly. 

For  making  concrete,  six  to  eight  parts  of  sharp  sand  or  clean 
rough  gravel,  to  o  ae  of  cement  may  be  used. 

For  stucco  work,  the  sand  must  be  clean,  the  undercoat  should  be 
three  parts  of  sand  to  one  of  cement,  and  the  finishing  coat,  equal 
parts  of  sharp  fine  sand  and  cement,  carefully  avoiding  mixing  the 
mortar  with  too  much  water.  The  brickwork  or  other  absorptive 
material  on  which  the  Portland  cement  is  to  be  used  must  be  first 
well  wetted. 


74 

Careful  attention  to  these  directions  is  most  essential  to  obtain  a 
satisfactory  result. 

When  making  cement  blocks  or  paving  slabs,  it  is  sometimes  con- 
sidered advisable  to  steep  them  in  a  solution  of  sodium  silicate  for  10 
to  14  days. 

The  cause  of  disintegration  of  mortar  during  frosty  weather  is  the 
expansion  due  to  the  conversion  of  the  water,  contained  in  the 
mortar,  into  ice,  the  expansion  equalling  a  10  %  increase  in  volume. 

Facings  and  Pointing. — There  is  always  considerable  risk  in 
using  a  brick  for  facing,  unless  it  is  known  to  stand  the  weather ; 
this  is  especially  the  case  with  red  bricks.  A  great  diversity  of 
opinion  and  practice  exists  as  to  pointing.  Ordinary  Tuck  pointing 
consists  of  well  raking  out  the  joints,  filling  in  with  coloured  mortar, 
and  then  laying  on  a  neat  parallel  joint  with  white  mortar  or  stopping. 
The  brickwork  is  also  in  most  cases  first  coloured  to  obtain  a 
uniform  appearance. 

Flat  pointing  is  merely  raking  out  the  course  joints  and  filling  in 
again  with  blue  mortar. 

Lime  is  much  improved  if  Portland  cement  is  added  thereto,  and 
well  mixed  with  it. 

Roman  cement  is  about  one-third  strength  of  Portland  cement. 

Plaster  of  Paris. 

Weight  per  striked  bushel  =  64  Ibs. 

„         „    cubic  foot        =  50   „ 

The  adhesive  power  of  Portland  cement  is  at  least  f  of  the  cohesive, 
when  new,  and  in  time  it  will  become  fully  equal  to  it. 

L.  J.  Af elder  and  R.  C.  Brown. 

Cement. — Magnesia  causes  expansion  and  crumbling  or  flaking  ; 

Sulphur  destroys  either  stone  or  concrete. 
Coefficient  of  expansion  of  cement  =  0-0000145 

„        „   iron       =  0-0000137  to  0-0000148 

The  Monier  system  of  making  concrete  has  proved  itself  from  5J 
to  12  times  as  strong  as  that  made  in  the  ordinary  way. 

It  has  been  proposed  to  coat  ironwork  which  is  to  be  imbedded  in 
brickwork  with  cement,  instead  of  asphalte  or  paint. 

Make  concrete  in  foundations  three  times  as  wide  as  the  brick  wall 
to  be  built  upon  it. 

Concrete  should  be  turned  at  least  twice  dry  and  twice  wet. 
About  25  gallons  water  required  per  cubic  yard  concrete. 

Volume  of  Spaces  per  Cent,  in  Concrete  Materials. 
Limestone,  crushed,  to  pass  through  3  inch  ring,  51  per  cent. 

A  AQ 

»  »»  J>  5>  » 

24       ,,         36        „ 

2  on 

»  Ay  „ 

14       „  42  „ 

Gravel,  to  pass  through  24       „  34  „ 


RESISTANCE   TO   CRUSHING.  75 

Shingle 33  per  cent. 

Thames  ballast  (including  sand)          .        .     .  17        „ 
Limestone  and  gravel  mixed  equally,  to  pass 

through  3  inch  ring 34        „ 

Good  concrete  will  bear  31-6  tons  per  square  foot  in  compression, 
and  3'1G  tons  per  square  foot  in  tension. 

Safe  Load  that  may  be  put  upon  a  superficial  foot  on — 

Granite  piers  .         .        .  =  40  tons  (crushing  commences  at  300  tons) 

Portland  stone  piers  .     .  =  13  „  ..  „  90  ,, 

Bath  stone  piers              .  =    6  „  .,  „  40  „ 
Brickwork  in  cement  and 

sand  (1  to  1) .         .     .  =    5  .,  ,.  „  40  „ 

Rubble  masonry             .  =    4  „  ..  ,  40  „ 

Firebrick   ......  as    6  „  ..  .,  50  „ 

Lias      Lime      (concrete 

foundations)        .         .  =    5  .,  „  „  20  „ 
Ordinary    brickwork    in 

lime  mortar            .     .  =    3  .,  .,  „  24  „ 

Pine  (yellow)         .         .  =  34  „  „  „  340  ,. 

Gravel  or  stiff  clay    .    .  =    2  „ 

Resistance  to  Crushing  (Stones). 

Per  square  inch.  Per  square  foot. 

Granite,    average 5*4  781 

Limestone      „          -. 3-06  441-1 

Sandstone       „ 1-87  268'9 

Victoria  stone  (granite  and  Portland  cement 
steeped  in  solution  of  flint),  average      .     .     3'71  534 

Ibs.  per  cubic  in. 

Crushing  commences  on  Sandstone,  strong .        .        .  5,000  to    9,000 
„  ordinary          .     .  3,000  to    5,000 

„  weak  .         .         .  2,000 

Limestone,  compact          .    .  8,000 
„  strong  magnesian  7,000 

„  weak  „          3,000 

„  granular     .         .  4,000  to    4,500 

Chalk 300  to       400 

Whinstone     ....  9,000  to  17,000 

Granite 6,000  to  11,000 

Mungall. 

Safe  Resistance  to  Loads  per  square  foot. 

Rock 13  tons. 

Chalk 4     n 

Solid  blue  clay  and  gravel 3  to    6     „ 

London  clay 2     „ 

12"  X  12"  wood  piles,  well  driven  to  4  blows  =  £"  20  to  30     ,' 


76  GAS  ENGINEER'S  POCKET-BOOK. 

A  factor  of  safety  of  one-fifth  of  crushing  weight,  if  the  load  be 
dead,  and  of  one-tenth,  if  the  load  be  live,  may  be  taken. 

In  laying  stone  the  joints  should  be  in  contact  from  face  to  tail. 
and  be  thoroughly  wetted  on  surface  before  laying. 

The  Test  for  the  Porosity  of  Stone. — Weigh  the  stone  when  dry 
and  weigh  it  after  immersion  in  a  pail  of  water.  If  a  sandstone 
absorbs  not  more  than  half  a  gallon  per  cubic  foot  it  is  a  good 
building  stone. 

Granite  consists  chiefly  of  quartz  50  to  60  per  cent.,  felspar  30  to 
40  per  cent.,  mica  10  per  cent.  ;  best  with  most  quartz  and  less  mica. 
The  composition  of  granite  is  about — 

Silica 72-07 

Alumina 14-81 

Oxide  of  iron    .         .         .         .          2-22 

Potash 5-11 

Soda          .        ....        *        »•**•      2-79 

Lime    .        .        .         .     -  ?  ' .          1-63 

Magnesia.     .  .        .        .        . •'"*      0-33 

Water,  &c.    .        ...        .  -.          1'09 

Portland  Stone. — Average  composition  : — 

Silica        .        .        .    " 1-20 

Carbonate  of  lime        .  .     .  95-16 

Carbonate  of  magnesia  .        .  1*20 

Iron  and  alumina         .  .     .  0'50 

Water  s.ncl  loss          .-  .        .  1'94 

Bitumen  Trace 


100-00 

Sandstone  should  consist  of  small  grains  of  quartz  and  only  small 
quantity  of  carbonate  of  lime  and  no  uncombined  particles  of  iron. 
Bath  stone  weight  is  123  Ibs.  per  foot  cube. 
York  stone  weight  156  Ibs.  per  foot  cube. — H.  Adams. 

2    inch  York  paving  weighs  per  square  foot  26    Ibs. 


39 

52 
65 

78 


Covering1  Power  of  Paint. 
10  Ibs.  white  lead  .         .         .  \ 

'  «3  superficial  yards,  1st  coat. 


4  pints  linseed  oil  .     . 

10  Ibs.  white  lead  .        .         .\ 

'         WO  superficial  yards,  2nd  coat. 


. 
1£  pints  spirits  of  turpentine  ) 


PAINTS. 


77 


10  Ibs.  white  lead 
2  oz.  litharge  . 
2  pints  linseed  oil 


113  superficial  yards,  3rd  and  4th  coats. 


2  pints  spirits  of  turpentine  .  J 

1  pint  varnish  will  cover  about  16  square  yards  one  coat. 

100  square  yards  of  painting,  4  coats,  will  require  about  48  Ibs. 
white  lead  or  colour  paint,  4  Ibs.  putty,  1\  quarts  oil,  1  Ib.  red  lead, 
\  Ib.  size,  2^  pints  turpentine,  \  Ib.  pumice-stone,  1  quire  glass-paper, 
1  Ib.  driers. 

Paint  should  contain  1  pint  turps  to  f  gallon  raw  and  \  gallon 
boiled  linseed  oil. 

A  good  paint  for  wooden  structures  should  consist  of  from  66  to  75 
per  cent,  pigment,  and  the  balance  oil,  £c. 

Boiled  linseed  oil  specific  gravity  should  be  '947 
Haw          „         „        .,  „  „       „   '932  to  -937 

„  „        „   flash  point  „       ,,   500°  F. 

Oxide  of  iron  paints  are  said  to  oxidize  their  oil  and  gradually 
destroy  it. 

White  lead  =  Pb.  C.  03, 

The  effect  of  sulphur  upon  white  lead  is  to  change  the  carbonate 
of  lead  into  a  sulphide,  which  becomes  soluble  in  condensed  moisture 
or  rain-water. 

To  Test  White  Lead. — If  pure  carbonate  it  will  not  lose  weight  at 
212°  F.  68  grains  should  be  entirely  dissolved  in  150  minims  of 
acetic  acid  diluted  with  1  fl.  oz.  distilled  water. 

Plumbago  mixed  with  hot  coal-tar  forms  a  good  coating  for  rough 
ironwork. 

It  is  said  that  none  of  the  metallic  oxides,  commonly  used  as 
pigments,  chemically  combine  with  the  linseed  oil  in  the  painting 
mixture. 

Thickness  of  Sheet  Glass. 


No.  or  Weight  in 
ozs.  per  sq.  ft. 

Thickness, 
inches. 

No.  or  Weight  in 
ozs.  per  sq.  ft. 

Thickness, 
inches. 

12 

•059 

21 

•100 

13 

•063 

24 

•111 

15 

•071 

26 

•125 

16 

•077 

32 

•154 

17 

•083 

36 

•167 

19 

•091 

42 

•200 

78 


GAS   ENGINEERS   POCKET-BOOK. 


The  Average  Weight  of  the  Materials  Covering  and  Bearing  on 
Roofs,  &c. ,  may  be  taken  roughly  as  follows  : — 


Description  of  Material. 

Weight 
per  Foot  Super. 

Common  rafters  

7    Ib 

f-in.  boarding         
1-Jn.         „           
Battens  3-in.  by  -'-in  
Felt    . 

2i  „ 
3J 
If 

Zinc 

If 

Corrugated  iron  . 
Slates     . 

$ 

Tiles   .... 

20 

Wind  |  pitch          about 

»            5         !>                      .....                          ,, 

V*   »    M 

Snow  
Slate,  1  in.  thick    
Paving-stone,  2  in.  thick    
Tiles,  1  in.  thick     
Marble,  2  in.  thick     

22 
25 

27 
5 
15 
28 
9 
28f 

In  calculating  the  safe  load  on  a  floor,  from  1^  cwt.  to  1£  cwt.  per 
superficial  foot  is  generally  allowed  for  ordinary  work,  and  from 
2  cwt.  to  4  cwt.  for  factories  and  warehouses,  including  the  weight 
of  the  floor  itself. 

Table  to  facilitate  the  Calculation  of  the  Area  of  any  Eoof. 


Rise  or  Pitch. 

Angle. 

Proportion. 

One-sixth  of  span      . 
One-quarter  of  span     .     . 

e              > 

18     25 
26     35 

1  to  1-05  or  1  to 
1  „  1-12      1 

It 

30    00 

1  „  1-20       1 

n 

One-third  of  span         .    . 

33     42 

1  „  1-20       1 

H 

One-half  of  span       .  •':;   .. 

45     00 

1  „  1-41       1 

If 

Two-thirds  of  span        .     . 

53     00 

1  „  1-67       1 

I* 

Three-quarters  of  span 

56     20 

1  „  1-80       1 

If 

Equilateral  .         ... 

60    00 

1  „  2-00       1 

2 

Whole  pitch      . 

63     30 

1  „  2-83    ,  1 

2£ 

Multiply  span  by  the  number  found  in  the  proportion  column  ; 
this  gives  the  superficial  area  of  the  roof  on  the  slope. 

Load  on  roof  may  be  taken  as  50  Ibs.  per  foot  superficial ;  this 
includes  weight  of  roof,  and  provides  for  extra  strains  thrown  on  it 
by  snow,  wind,  &c.,  from  5  to  6  tons  safe  load  per  inch  of  section  of 
ties. 

Slates  should  not  be  laid  at  less  than  26 £°  with  horizontal. 


SLATING.  79 

Roof  Coverings. — Roofs  covered  with  slates  or  shingles  should  have 
a  pitch  of  not  less  than  one-fourth  the  width  of  span  ;  but  the  roof 
may  be  truncated  if  a  lower  pitch  is  required. 

Allowance  for  Wind  and  Snow. 

Weight  of  snow  on  horizontal  surface        .  =  say,  15-5  Ibs.  per  sq.  ft. 
Wind  pressure  on  surface  at  right  angles 

to  line  of  impact =    „     24*6    „          „ 

Do.        do.     in  specially  exposed  positions  =    „     31'0    ,,          „ 

D.  K.  Clark. 

Laths  for  Queens  and  slates          should  be  12  inches  apart. 

„          Duchess  and  Princesses         „         10£     „          „ 

Countesses  8i     , 


Provide  for  removing  Rainfall  per  Hour. 

From  roofs      ...         .5     inches  in  depth. 
Flagged  surface          ...     2          „  „ 

Gravelled        .        .         .         .     0-5       „  „ 

Meadows,  or  grass  plots      .     .     0'2       „  „ 

Paved  surfaces        .        .        .1  „  „ 

Rainfall,  maximum,  may  be  taken  as  1J  inches  in  21  hours  in  cal- 
culating size  of  rain-water  pipes. 


SLATES. 

Sizes. 

Squares  covered 
by  1000. 

Weight 
per  1000. 

Weight 
per  square. 

Doubles 

13  in.  X    6  in. 

2 

15  cwts. 

7i  cwts. 

Ladies      .     . 

16  „   X    8  „ 

4i 

25      „ 

51      „ 

Countesses    . 

20  „   X  10  „ 

7 

40      „ 

5f      „ 

Duchesses     . 

24  „   X  12  „ 

10 

60      „ 

6        „ 

To  test  slates,  place  on  edge  half  immersed  in  water  for  12  hours  ; 
if  water  has  spread  up  to  near  the  top  of  slate,  reject  it ;  if  not  risen 
more  than  \  inch,  may  be  considered  non-absorbent.  Or  weigh  a 
slate  before  and  after  immersion,  and  the  difference  will  show 
quantity  of  water  absorbed  ;  should  not  be  more  than  ^th  part  of 
weight  of  slate. 

Good  slates  should  be  compact,  with  a  metallic  ring  when  struck, 
the  edge  not  friable,  incapable  of  absorbing  or  retaining  much 
moisture  hard  and  rough  to  the  touch. 

Weight  of  Zinc  Slating  Nails. 

1  inch  go  about  340  to  the  pound. 
H     »  »        290 

H    »          »        220  „ 

if  „       „      ™o 

2  90 


80 


GAS   iiSGlNEER'S   POCKET-BOOK. 


Curved  roofs  of  25  to  30  feet  span,  rise  £  span  may  be  used  if 
10  B.W.Gr.  corrugated  iron  sheets,  rivetted  together  with  tie  rods 
every  few  feet,  continuous  angle  iron  skewbacks,  and  thin  rods  from 
the  centre,  to  prevent  sagging  in  tie  rods. 

Use  two  nails  to  fasten  each  slate,  say  1J  inch  long,  of  copper. 
Lowest  coarse  of  laths  for  slates  should  be  1  inch  higher  than  the 
o  there. 

Fall  in  gutters  should  be  1  in  50  at  least. 

Thick  asphalted  or  inodorous  felt  is  made  in  rolls  25  yards  long  by 
32  inches  wide. 

Sheathing  felt  is  made  in  sheets  32  inches  X  20  inches. 
Dryhair      „  .,  ,         34       „       X  20       „ 

No.  0, 12  oz.    per  sheet.  No.  3,  2    Ibs.  per  sheet. 

No.  1,  1    Ib.         „  No.  4,  2i   „ 

No.  2,  H  Ibs.         „  No.  5,  3     „ 

Willesden  roofing  is  supplied  in  rolls  of  50  and  100  yards  X  27 
inches  wide  (in  two  qualities),  or  54  inches  wide  if  required. 

Allport's  patent  wire-wove  waterproof  roofing,  a  strong  covering 
material  made  upon  japanned  or  tinned  steel  wire  gauze,  is  made  in 
sheets  40  in.  X  28  in.,  42  in.  X  26  in.,  49  in.  X  26  in. ;  a  lighter 
quality  is  made  in  sheets  42  in.  x  26  in. 

In  laying  lead,  where  possible  avoid  soldered  joints. 

Use  not  more  than  10  feet  sheets,  and  then  fix  roll. 

Lay  to  a  slope  of  not  less  than  1  inch  in  10  feet. 

Weight  and  Thickness  of  Sheet  Lead. 


Weight  in  Ibs. 
per  square  foot. 

Thickness  in 
inches. 

Weight  in  Ibs. 
per  square  foot. 

Thickness  in 
inches. 

1 

•017 

7 

•118 

2 

•034 

8 

•135 

3 

•051 

9 

•152 

4 

•068 

10 

•169 

5 

•085 

11 

•186 

6 

•101 

12                           -203 

Usual  Thickness  of  Sheet  Lead  in  use.  — For  aprons,  5  Ibs.  per 
square  foot ;  for  roofs,  flats,  gutters,  &c.,  7  to  &  Ibs.  ;  for  hips  and 
ridges,  6  to  8  Ibs. 

Proper  Proportion  of  Tread  to  Riser  on  Staircase,  projection  of 
Nosing  not  included. 

Width  of  tread  12    inches,  rise  should  be  5£  inches. 


11 

io2 

I) 


6 

6* 
6* 
6| 


PROPORTIONS    OF    TREADS    AND    RISERS. 


81 


Another  method  is  to  multiply  the  tread  by  the  riser,  both  in 
inches,  and  the  sums  should  equal  72. 

Another  rule — 

Width  of  tread    6  inches,  height  of  risers  8J  inches. 
•       »? 


10 

11 

12 
18 


A  further  method  of  obtaining  the  Proportion  of  Stair  Treads  and 
Risers— 


1*"  IS"  fc"  6'  0 

Thus  9-inch  tread  requires  7-inch  risers. 

Stone  steps  upheld  both  ends  should  have  6-inch  bearing  at  each  end. 
„        „          „       one  end  only  should  have  9  inches  built  into  wall. 

Timber. — Timber  should  never  be  so  enclosed  in  a  building  that  the 
air  cannot  circulate  around  it,  or  it  will  decompose.  When  timber  has 
to  be  fixed  near  the  ground,  or  in  any  damp  place,  it  may  be  coated 
with  a  thin  solution  of  coal  tar  and  fish  oil  mixed  with  finely 
powdered  clinkers  from  the  forge. 

All  timber  should  be  thoroughly  seasoned  before  any  preservative 
is  used. 

One  method  of  preserving  timber  is  to  dry  it  and  apply  a  weak 
solution  of  corrosive  sublimate,  or  of  nitric  acid  and  water,  and  then 
paint  it  with  white  lead  and  oil. 

Another  method  is  to  soak  the  timber  for  from  2  to  12  hours  in 
melted  napthalene  at  a  temperature  of  about  200°  F. 

The  timber  used  in  building  operations  for  carpenter's  work  is 
imported  from  Memel,  Riga,  Dantzic  and  Sweden  ;  and  that  for 
joiner's  work  from  Christiania,  Stockholm,  Gefle,  Onega  and  other 
northern  ports. 

In  selecting  timber  the  most  convenient  sizes  are  12  inches  square  ; 

G.E.  a 


82 


GAS    ENGINEER  !?    POCKET-BOOK. 


choose  the  brightest  in  colour,  where  the  strong  red  grain  appears  to 
rise  to  the  surface ;  avoid  spongy  hearts,  porous  grain,  and  dead 
knots.  (La-xton.} 

(1)  Seasoned  timber  is  about  twice  as  strong  as  green  timber ; 
(2)  well  seasoned  timber  loses  some  of  its  strength  when  moisture 
is  re-absorbed  ;  (3)  when  free  from  knots  and  flaws  timber  in  large 
pieces  is  as  strong,  per  inch  section,  as  when  in  smaller  pieces ; 
(4)  knots  weaken  timber  as  greatly  whether  it  is  for  use  as  a  strut  or 
as  a  tie  ;  (5)  long  leafed  pine  is  as  strong  as  average  oak  ;  (6)  bleeding 
a  tree  does  not  impair  the  quality  of  its  timber. 

Timber  joists  should,  where  possible,  be  left  open  to  the  atmosphere 
at  the  ends,  and  not  built  into  the  wall.  Iron  joists  should  have  a 
space  at  the  ends  to  allow  of  expansion,  and  should  be  built  in 
pockets. 

Planks  are  11  inches  wide  ;  deals.  9  inches  ;  and  battens.  7  inches. 

Loads  on  Floors. 

Floors  of  factories,  workshops,  and  warehouses  should  be  able  to 
carry  a  load  of  2£  cwt.  per  square  foot.  Floors  of  large  buildings  such 
as  public  buildings,  lecture  halls,  churches,  and  chapels,  should  be 
able  to  carry  a  load  of  1£  cwt.  per  square  foot.  Floors  of  dwelling- 
houses  need  only  be  strong  enough  to  carry  a  load  of  120  to  140  Ibs. 
per  square  foot.  Basement  floor  joists  should  rest  on  sleepers,  which 
should  not  be  laid  on  stone. 

(U.S.  Assoc.  of  Superdts.  of  Bridges  and  Buildings.) 


In  Tension. 

In  Compression. 

Shearing. 

With  Grain. 

Across. 

With  Grain. 

Across. 

With  Grain. 

Across. 

White  Oak 

l,0001bs. 

200  Ibs. 

900  Ibs. 

500  Ibs. 

200  Ibs. 

1,000  Ibs. 

„      Pine 

700    „ 

50   „ 

700    „ 

200    „ 

100    ., 

500  „ 

Red 

900    „ 

50    „ 

800    „ 

200    „ 

Norway  „ 

800    „ 

— 

800    „ 

200    „ 

Cedar  .     . 

800    ,. 

— 

800    „ 

200    ., 

— 

400  „ 

Chestnut  . 

900    „ 

— 

1,000    „ 

250    „ 

150    .. 

4,00  „ 

All  per  square  inch  safe  stresses. 

To  calculate  dead  distributed  safe  load  on  timber  (rectangular 
section — floor  joists,  &c.) — 

1,100,  if  fir 
4  ft  x  (P  x  1.900,  if  oak 

=  load  in  Ibs. 


b  =  breadth  in  inches. 
d  =  depth      .,        ,. 
L  =  span        „ 


(R.  A.  Rule.) 


A  crowd  of  men  closely  packed  =  120  Ibs.  per  square  foot. 
A  cart  horse  =14  cwt. 


STRENGTH    OF   TIMBER.  83 

Strength  of  Timber.     (Ranldne's  "  Civil  Engineering.") 


Wood. 

Resistance  to  Shearing  per  Square  Inch  in  Ibs. 

Along  the  Fibres. 

Across  the  Fibres. 

Oak     
Ash  and  elm    . 
Spruce  or  white  fir      . 
Red  pine  

2,300 
1,400 
600 
500  to  800 

4,000 

Wood. 

Weight  required  to 
crush  1  Square  Inch 
in  the  direction  of  the 
Fibres. 

Weight  required  to 
indent  1  Square  Inch 
2\j  inch  deep  across 
the  Grain. 

Ash   
Fir  (white) 
Fir  (yellow) 
Oak  
Pine     

Cwt. 
80 
50 
52 
80J 
36 

Cwt. 
12i 
5£ 
5J 

18 

H 

Wood. 

Weight  required  to 
break  a  Stick  1  Inch 
Square  by  Tensile 
Stress. 

Ash  

Tons. 
41 

Fir  (white)  
Fir  (yellow)      ... 
Oak       
Pine  • 

H 

P 

1 

Time  required  for  Seasoning.      (Laslett.) 


Pieces  24  inches  and  upward  square  require  about 
Pieces  under  24  inches  to  20 


20 


16 


Oak. 

Months. 

,       26 

22 

18 

14 

10 

6 


Fir. 

Months. 
13 
11 

9 

7 

5 

3 


G2 


84 


GAS  ENGINEER'S  POCKET-BOOK. 


Breaking  Load  in  Tons  on  Square  Yellow  Pine  Pillars,  firmly 
fixed  and  equally  loaded. 

6  7  8  91011 12 


I 

I 

li. 

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no 
120 
130 
140 

160 

170 


3456 

Side  of  Square  Pine  Pillar  in  inches. 


STRENGTH    OF    PINE    BEAMS. 


85 


Diagram  showing  Safe  Centre  Load  on  Yellow  Pine  Beams  1  Inch  wide ; 
factor  of  safety,  one  fifth.    Pitch  Pine  will  carry  one  fourth  more. 

To  find  necessary  width         actual  load 


load  on  diagram. 
10"    12"    14'' 
9"   n"         10     16"      18"         20  30 


40 


900 


800 


700 


600 


500 


400 


5  10  15  20  25  30  35 

Feet  Span.  For  Distributed  Load  multiply  by  2. 


86 


GAS  ENGINEER'S  POCKET-BOOK. 


Distributed  Safe  Load  on  Timber  Joists  1  Inch  wide. 

Load  in  Cwts. 
30  20 


6"  5"  4' 

Depth  of  Beam. 


DEAD    AND    LIVE    LOADS. 


87 


Average  Dead  Load  of  different  Classes  of  Material  that  may  have 
to  be  provided  for  in  the  Building  Trade.     (F.  Crocker.) 


Material. 

Per  Cubic  Foot. 

Slate         ... 

180 

Ibs. 

Lime  (stone)        ...                 .... 

60 

Lime  (ground)         

54 

j) 

Portland  cement  

85 

yj 

Tiles         

108 

5) 

Asphalt         .                 

140 

55 

Brick        ... 

130 

5 

Brickwork  in  mortar    . 

112 

Coal  

80 

Concrete      

130 

5 

Mud  . 

100 

Gravel  

110 

5 
j 

Masonry  140 

Mortar  112 

| 

Sand        100 

Snow    5  to  12 

55 

Timber  (oak)   1           50 

55 

„       (deal)       i           32 

Water       621 

jj 

Seeds    50 

5? 

Hay  ,             8 

55 

Straw  j            4£ 

55 

Average  Weight  of  various  Live  Loads. 


Description. 

Weight. 

Man     .... 
Crowd  of  men  per  foot 
,,              ,,      densely 
Horse  (heavy) 

»      (light)      - 

Ox  . 
Cow     .        ..        .   '     . 

Pig   •         •         •         - 
Sheep   (small)    . 
„        (large)        . 
Single-horse  load,  inclu 
Pair-horse             „ 

superficial 
packed    . 

ding  horse  and  vehicle 

M             >»             5? 

about 

from 

(heavy) 
(heavy) 

150 
86 
120 
14 
8 
10 
6^ 
1  to  2 
65 
90 
4 

Ibs. 

j» 

?5 

cwt. 

)J 

»5 

Ibs. 

;> 

tons. 

» 

Theoretical  H.P.  of  falling  water  =  '00189  Q.H. 

Q  =  volume  in  cubic  feet  of  water  flowing  per  minute. 
H  =  fall  of  water  in  feet. 


GAS  ENGINEER'S  POCKET  BOOK. 

Power  of  water  fall  (theoretically)  :— 

Gallons  per  minute  x  lOlbs.  x  height  of  fall  in  feet  —  33,000  =  H.P. 
Head  of  water  in  feet  x  '434  =  Ibs.  per  square  inch. 
Velocity  of  water  in  a  uniform  diameter  cast  iron  pipe  of  smooth 
bore  = 


48  A  f<f  +  *  dieter  in  feet. 

length  in  feet  (Hawksley.) 

Quantity  of  water  discharged  from  a  channel  or  pipe  = 


100    sectional    area    of     /  head  in  feet 

current  in  square  feet  V  length  in  feet  x  hydraulic  mean  dePth- 

(Downing.) 

Frictional  Loss  in  Hydraulic  Bams. 

("  Hicks'  Formula.") 
F  =  -04  P 
D 

P  =  total  load  in  Ibs. 

D  —  diameter  in  inches. 

F  =  frictional  resistance  in  Ibs. 

1  inch  mercury  =  13*4  inches  water  =  345'4  millimetres. 

3^&ths  inch  mercury  =  12  inches  water. 

1  gallon  salt  water     =  10-272  Ibs. 

1  ton         „       „         =35  cubic  feet  =218  gallons. 

Specific  Heat. 

Specific  heat  =  proportion  of  heat  required  to  heat  a  substance 
through  1  degree  compared  with  equal  weight  of  water.  Specific  heat 
of  water  =  1. 

Specific  Heats. 


Brickwork 
Chalk  .... 
Charcoal  . 
Coal  (anthracite)     . 
„     (bituminous)   . 
Coke 

•192 
•215 
•241 
•201 
•241 
•203 

Glass 
Graphite 
Ice    . 

Stonework   . 
Wood  average  . 

.     -190 
.     -202 
.     -504 
.     -197 
.     -550 

Speed  of  Sound. 

In  air  at  0°  =      1.093  feet  per  second. 
Add  2  feet  for  every  degree  Centigrade. 

In  water       =     4,780  feet  per  second. 
In  copper     =    11,666    „      „        „ 
In  iron         =    16,822    „      „         „ 


RADIANT   HEAT. 


89 


Comparative  Powers  of  Substances  for  Reflecting  Kadiant  Heat. 


Polished  brass 
Silver    . 
Tin    . 
Steel 


100 
90 
80 
60 


Lead   . 
Glass 
Lampblack . 


(50 

10 

0 


Table  of  Coefficients  of  Linear  Expansion  for  1  Degree  Centigrade 


Glass 
Platinum 
Cast  iron 
Wrought  iron 
Copper 
Lead 
Zinc 
Brass 


•0000085 

•0000085 

•00001 

•000012 

•000017 

•000028 

•00003 

•000019 


12OOOO 

Tooooo 

85000 
58000 
35000 
34000 
52000 


Specimens  vary  in  their  expansions,  and  the  above  Table  is  only 
approximate. 

Factors  of  Safety.     (Umvin.) 


Live  Load. 

In  Structures 

Dead  Load. 

Temporary 
Structures. 

Permanent 
Structures. 

subjected 
to  Shocks. 

Wrought  iron  and  steel 

8 

4 

4  to  5 

10 

Cast  iron         .        .     . 

r> 

4 

f> 

10 

Timber 



4 

10 

Brickwork       .         .     . 





6 

Masonry 

20 

— 

20  to  30 

One  B.T.  unit  oi  electricity  =  1,000  watts  for  1  hour. 
One  H.P.  =  746  watts. 

One  B.T.  unit  of  electricity  =  li  HP.  very  nearly. 
Sizes  of  Wire  Gauges  in  Decimals  of  an  Inch. 


Size. 

Birmingham 
Wire  Gauge. 

Imperial 
Standard 
Gauge. 

Size. 

Birmingham 
Wire  Gauge. 

Imperial 
Standard 
Gauge. 

1 

•312 

•300 

13 

•093 

•092 

2 

•281 

•276 

14 

•078 

•080 

3 

•265 

•252 

15 

•070 

•072 

4 

•234 

•232 

16 

•062 

•064 

5 

•218 

•212 

17 

•054 

•056 

6 

•203 

•192 

18 

•046 

•048 

7 

•187 

•176 

19 

•042 

•040 

8 

•171 

•160 

20 

•038 

•036 

9 

•156 

•144 

21 

•034 

•032 

10 

•no 

•128 

22 

•031 

•028 

11 

•125 

•116 

23 

•028 

•024 

12 

•109 

•104 

24 

•025 

•022 

90 


GAS  ENGINEER'S  POCKET-BOOK 


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GAS  ENGINEER'S  POCKET-BOOK. 


American  and  Birmingham  Gauges. 
1  mil.  is  equal  to  ^^f  inch. 


No. 

American. 
Diameter  in 

Mils. 

Birmingham. 
Diameter  in 

Mils. 

No. 

American. 
Diameter  in 
Mils. 

Birmingham 
Diameter  in 

Mils. 

0000 

460 

454 

8 

128-5 

165 

000 

409-6 

425 

9 

114-4 

148 

00 

364-8 

380 

10 

101-9 

134 

0 

324-9 

340 

12 

80-8 

109 

1 

289-3 

300 

14 

64-1 

83 

2 

257-6 

284 

16 

50-8 

65 

3 

229-4 

259 

18 

40-3 

49 

4 

204-3 

238 

20 

32 

35 

5 

181-9 

220 

30 

10 

12 

6 

162 

203 

40 

3-1 

5-8 

7 

144-3 

180 

Weight  of  Vieille-Montagne  Zinc  Sheeting  per  Square  Foot. 


Gauge. 

Lb. 

Ozs. 

Drms.   1  Gauge. 

Lb. 

Ozs.    Drms. 

9 

0 

10 

5 

14 

1 

2 

12 

10 

0 

11 

7 

15 

1 

5 

12 

11 

0 

13 

5 

16 

1 

8  . 

12 

12 

0 

15 

2 

17 

1 

11 

11 

13 

1 

0 

15 

18 

1 

14 

11 

Thickness  of  Tin  Plates. 


ic  =  30  B.  G. 
ix  =  28-1 
ixx  =  26-8 

ixxx  =  25-8 
ixxxx  =  24-8 
ixxxxx  =  23-9 

ixxxxxx  =  23-1 
DC  =  27-8 
DX  =  25-6 

DXX  =  24-2 
DXXX  =  23-0 
DXXXX  =  22-0 

Table  Showing  the  Number  of  Square  Feet  a  Cwt.  of  Sheet  Lead 
will  cover  on  a  Flat  Roof  or  Gutter. 


Thickness.     Weight  per 
Inch.        Square  Foot. 

4) 

(  28  feet  0  inches. 

ith              5  V    Milled  lead 

\22    „     5       „ 

ith              C.  ) 

18    „     8       „ 

7  \ 

116    „     0      „ 

1 

h            jg  L  Cast  lead 

14    „     0      „ 
12    „     5J     „ 
H    „     3       „ 

11 

10    .,     2       „ 

£th            12  j 

I'm     *       „ 

Specific  gravity  =  11-325. 
Weight  per  cubic  foot  =  708  Ibs. 
330  l-}-inch  galvanised  slate  nails  weigh  1  Ib. 
50  5-inch  lead  nails  weigh  3  Ibs.  2|  ozs. 


BOX  TINPLATEI. 
Box  Tinplates:  Dimensions  and  Weights. 


97 


Description. 

Mark. 

Dimensions 
of 
Sheets. 

Number 
of  Sheets 
n  a  Box. 

Weight 
of  Each 
Box. 

Inches. 

Sheets. 

Lbs. 

Common  No.  1  ... 

1C 

14x10 

225 

108 

Ores-  No.  1        

IX 

14x10 

225 

136 

Two  crosses  No.  1 

IXX 

14X10 

225 

157 

Thiee  crosses  No.  1 

IXXX 

14x10 

225 

178 

Four  crosses  No.  1 

1XXXX 

14x10 

225 

199 

Common  No.  1  ... 

1C 

14x20 

112 

108 

Cross  No.  1       

IX 

14x20 

112 

136 

Two  crosses  No.  1 

IXX 

14x20 

iia 

157 

Three  crosses  No.  1     ... 

IXXX 

14x20 

112 

178 

Four  crosses  No.  1 

IXXXX 

14x20 

112 

199 

Common  No.  1  

1C 

28x20 

56 

108 

Cross  No.  1       

IX 

28x20 

56 

136 

Two  crosses  No.  1 

IXX 

28x20 

56 

157 

Three  crosses  No.  1     ... 

IXXX 

28x20 

56 

178 

Four  crosses  No.  1 

IXXXX 

28x20 

56 

199 

Common  No.  1 

1C 

12x12 

225 

108 

Cross  No.  1        

IX 

12x12 

225 

136 

Two  crosses  No.  1 

IXX 

12x12 

225 

157 

Three  crosses  No.  1     ... 

IXXX 

12x12 

225 

178 

Four  crosses  No.  1 

IXXXX 

12x12 

225 

199 

Com  mon  doubles 

DC 

17x12^ 

100 

94 

Cross  doubles    ... 

DX 

17x12^ 

100 

122 

Two-  cross  doubles 

DXX 

17xl2i 

100 

143 

Three-cross  doubles     ... 

DXXX 

17x12* 

100 

164 

Fou  r-cross  doubles 

DXXXX 

17xl2± 

100 

185 

Com  mon  doubles 

DC 

17x25 

50 

94 

Cross  doubles   ... 

DX 

17x25 

50 

122 

Two-  cross  doubles 

DXX 

17x25 

50 

143 

Three-cross  doubles     ... 

DXXX 

17x25 

50 

164 

Four-cross  doubles 

DXXXX 

17x25 

50 

185 

Common  doubles 

DC 

34x25 

25 

94 

Cross  doubles    ... 

DX 

34x25 

25 

122 

Two-cross  doubles 

DXX 

34x25 

25 

143 

Three-cross  doubles     ... 

DXXX 

34x25 

25 

164 

Four-cross  doubles 

DXXXX 

34  x  25 

25 

185 

Small  common  doubles 

SDC 

15x11 

200 

167 

Small  cross  doubles 

SDX 

15x11 

200 

188 

Small  two-cross  doubles 

SDXX 

15x11 

200 

209 

Small  three-cross  doubles 

SDXXX 

15x11 

200 

230 

Small  four-cross  doubles 

S  DXXXX 

15x11 

200 

251 

Small  common  doubles 

SDC 

15x22 

100 

167 

Small  cross  doubles     ... 

SDX 

15  x  22 

100 

188 

Small  two-cross  doubles 

SDXX 

15x22 

100 

209 

Small  three-cross  doubles 

SDXXX 

15x22 

100 

230 

Small  four-cross  doubles 

S  DXXXX 

15x22 

100 

251 

Note.^- The  weights  of  the  cross-marked  boxes  advance  at  the  rate 
of  21  Ibs.  per  Cross. 


G.E, 


98 


GAS  ENGINEER'S  POCKET-BOOK. 


Weight  of  Copper  Nails, 
inch  weigh  about     3  Ibs.  4  ozs.  per  1,000. 
9   „   9    „      „      „ 

•  „        „          „       11    „    4    „      „      „ 

oq  4. 

5T  »»  ))  *«'        55        *        »  55  M 

40    „    0 


Corrugated  Iron  Roof  Sheeting. 


B.  Wire 
Gauge. 

Size  of  Sheets. 

Weight  per 
Square 
Foot. 

Weight  per 
100  Square 
Feet. 

Square 
Feet 
per  Ton. 

Feet. 

Cwt. 

Qrs. 

Lbs. 

No.  16 

6  X  2  to  8  X  3 

3-5 

3 

0 

14 

800 

18 

6  x  2  to  8  x  3 

2-6 

2 

1 

6 

1,000 

•20 

6  x  2  to  8  X  3 

2-05 

1 

3 

6 

1,250 

22 

6  x  2  to  7  X  2£ 

1-75 

1 

2 

7 

1,550 

24 

6  x  2  to  7  x  2£ 

1-36 

1 

0 

24 

1,880 

26 

6  x  2  to  7  x  2J 

1-12 

1 

0 

6 

2,170 

ith  weight  to  be  added  for  lappage. 


Relative  Electrical  Conductivity  of  Metals. 


Silver 
Copper 
Brass 
Tin    . 


100 
74 
24 
15 


Iron 
Lead    . 
Platinum 
Bismuth 


12 

8 
8 
2 


Melting  Point  of  Metals. 


°F. 

Specific 
Heat. 

'F. 

Specific 
Heat. 

Aluminium 

Nickel  .         .     . 

2,810 

•109 

(pure)    .     . 

1,300 

•234 

Platinum     .     . 

3,080 

•039 

Antimony 

810 

•051 

Silver 

1,832 

•057 

Bismuth  .     .     . 
Brass    .        .     . 

507 
1,650 

•031 
•094 

Steel  (hard)     . 
Steel  (mild)     . 

2,370 
2,550 

Vll7 

Copper 
Gold    .        .    . 

2,166 

•095 
•032 

Tin       .        .     . 

Zinc  . 

446 
736 

•057 
•096 

Iron  (cast)   .     . 

1,920  to 

•130 

Phosphorus  .     . 

110 

•288 

2,012 

Spermaceti 

120 

„     (wrought) 

2,912 

•110 

Sulphur        .     . 

230 

•203 

Lead 

612 

•031 

Tallow 

92 

Manganese  .     . 

— 

•144 

Wax  (bees')       . 

150 

Mercury  . 

-  39 

•033 

(paraffin). 

114 

SHRINKAGE    OF   CASTINGS.  99 

Cast  iron  usually  consists  of  from  3  to  5  per  cent,  of  carbon,  which 
in  white  iron  is  thoroughly  combined  with  the  iron,  and  in  grey  iron 
(H5  to  1-5  per  cent,  is  combined,  and  the  remainder  crystallises 
separately  as  graphite. 

Cast  iron  contracts  £  inch  per  foot ;  patterns  should  therefore  be 
that  amount  larger,  or  say  1  per  cent. 


Usual  Allowance  for  Shrinkage  of  Castings  per  Foot. 


Parts  of  an  Inch. 

For  cast  iron  pipes    . 
,,          „         beams  and  girders  . 

.     -125 
.     -1 

— 

1 

»>                    »J 

cylinders,  large   . 

.     -094 

= 

»                    ?> 

„          small 

.     -06 

= 

JL 

Brass 

.     -17 

— 

Lead     . 

i 

.     -31 

— 

Zinc  . 

•25 

_ 

4- 

Copper 

.     '17 

_ 

4 

Tin   . 

•25 

16 

Bismuth 



,     -154 

z 

i 

Babbitt  Metal. 

Proportions  of  Babbitt  metal  for  running  in  cast  iron  boxes  — 

1.  For  light  work  .    .         .50  tin,  5  antimony,  1  copper. 

2.  „     heavy    „    .         .     .    46    „    8         ,,          4       .. 

Attrition  Metal. 

One  copper,  3  best  tin,  2  regulus  of  antimony  ;  heat  separately  and 
then  mix  and  add  3  more  parts  tin  ;  on  remelting  add  twice  the 
quantity  of  tin  to  one  of  above  mixture. 

Delta  Metal. 

Cast,—  Copper,  55-94  per  cent.  ;  zinc,  41  -61  per  cent.  ;  iron,  '81  per 
cent.  ;  manganese,  -81  per  cent.  ;  lead,  '72  per  cent.  ;  phosphorus, 
•013  per  cent.  ;  nickel,  a  trace. 

Wrought.—  Copper,  55-8  per  cent.  ;  zinc,  40-07  per  cent.  ;  lead, 
1-82  per  cent.  ;  iron,  1'28  per  cent.  ;  manganese,  '96  per  cent.  ; 
phosphorus,  -Oil  per  cent.  ;  nickel,  a  trace. 

Boiled.  —  Copper,  55'82  per  cent.  ;  zinc,  41-41  per  cent.  ;  manganese, 
1-38  per  cent.  ;  iron,  -86  per  cent.  ;  lead,  -76  per  cent.  ;  nickel,  '06  per 
cent.  ;  phosphorus,  a  trace. 

Hot-punched  Metal.—  Copper,  54-22  per  cent.  ;  zinc,  42-25  per  cent.; 
lead,  1-1  per  cent.  ;  manganese,  1'09  per  cent.  ;  iron,  -99  per  cent.  ; 
nickel,  -16  per  cent.  ;  phosphorus,  '02  per  cent. 

Tensile  strength  of  cast      =  35  tons  per  square  inch. 

„  „          „   forged  =  42     „      „    „  „ 

Will  not  weld,  but  can  be  soldered. 

H2 


100 


GAS  ENGINEER'S  POCKET-BOOK. 


To  Case  harden. — Make  the  surface  bright,  heat  to  red  heat,  rub 
with  prussiate  of  potash,  and  quench  in  water.  Or,  better,  heat  the  iron 
in  a  close  box  filled  with  bone  dust  and  cuttings  of  horn  and  leather. 
(Unwin.) 


Colours  and  Temperatures  for  Hardening  Tools. 

Pale  straw  =  430°F.  for  lancets,  &c. 

Dark  yellow  =  470°F.  „  razors. 

„      straw  =  470°F.  „  penknives. 

Clay  yellow  =  490°F.  „  chisels  and  shears. 

Brown    „  =  500°F.  „  adzes  and  plane  irons. 

Very  pale  purple     =  520°F.  .,  table  knives. 

Light  purple  =  530°F.  .,  swords  and  watch  springs. 

Dark       „  =  550°F.  .,  softer  swords  and  watch  springs. 

„    blue  =  570°F.  „  small  fine  saws. 

Blue  =  590°F.  .,  large  saws. 

Pale  blue  =  610°F.  „  saws,  the  teeth  of  which  are  set 

with  pliers. 

Greenish  blue  =  630°F.  „  very  soft  temper. 

To  unite  two  pieces  of  lead,  the  surfaces  to  be  joined  are  scraped 
bright,  and  between  them  there  is  immediately  inserted  a  very  thin 
leaf  of  lead  amalgam — that  is,  lead-foil  that  has  been  saturated  with 
mercury.  On  passing  a  soldering  iron  along  the  seam,  or  by  heating 
in  some  other  way,  the  mercury  is  vaporised  and  driven  off.  The 
lead  is  left  free  in  an  extremely  fine  state  of  division,  and  in  that  state 
readily  fuses,  and  forms  a  sound  joint  between  the  adjacent  parts. 


STRENGTHS   AND    MODULUS    OF    ELASTICITY. 


101 


1 1  I  1 1  I  I  1 1  I  I  1 1  1 1  1 1  I  III  III  I  g"  I  g"  I  8"S  I 


•s 

bo 


3 1 1 1 3 1 1  r 3 1 3 1 3 1  333  1 3 1  1 3- 1  i  i  i  i  i 

<M  rH  <N         *O         SO         ^  rH 


I  ^  I    I  °-  I    I    I    I    I  *   I    I    I    I    I    I    I    I    I    I 

(MO  S 


S 


r-t  if  IM  lO  •«*< 


2     •  TJ  -3 

:*;•  I  1  ll. 

s  •  s  i  i  i 

P<  O  eS  d)     . 

'-I  s  ^  ^          : 


102 


GAS  ENGINEER'S  POCKET-BOOK. 


PROPORTIONS   OF  BOLTS  AND  NUTS. 
(Unwin.) 

Hexagon  Nuts. 

Diameter  across  flats    =  D  =  l-od    +  0-18  to  l-5d    -f-  0-44  if  rough. 

„          „          „  =  l-od    +  0-06  to  l-5d    +  0  18  if  bright. 

„  „  angles  =  Dx  =  l-75d  +  0'16  to  l-7std  +  0-4  if  rough. 
=  i-75d  +  0-07  to  l-75d  +  0'2  if  bright. 
Height  of  nut  =  d  —  diameter  of  bolt. 

„      „  lock  nut  =  Y 

Square  Nuts. 

Diameter  across  flats      =  l.od   +  0'18  to  lmod    +  0'44  if  rough. 

„          „         „  =  l-nd    +  0-06  to  l-od    +  0-18  if  bright. 

'„          .,        angles  =  2-l2d  +  0-25  to  2'l2d  +  0-6    if  rough. 

„          „  „        =  2-l2d  +  0-08  to  2!12d  -j-  0-25  if  bright. 

Head  of  bolt  may  be  square,  hexagonal,  or  circular.    Its  height  fd  to  d. 

Washers. 

Thickness,  0'15d  ;  diameter  |Dr 

Small  washers  are  usually  14  B.W.G.  or  0'083  inches  thick. 
Washers  for  wood  may  be  3d  in  diameter  and  Om'6d  in  thickness. 

Length  of  spanner  =  \od  to  I8d. 

A  workman  exerting  a  pull  of  301bs.  on  a  spanner  will  cause 
tension  in  the  bolt  =  2,460  Ibs.,  a  force  enough  .to  break  a  f  inch  bolt, 
and  to  seriously  strain  a  £  inch  bolt.  Therefore  bolts  of  less  ttan 
f  inch  diameter  should  not  be  used  for  joints  requiring  to  be  tightly 
screwed  up. 

Number  of  Cold-punched  Nuts  per  100  Lbs. 


Inch. 

Square.      I    Hexagon. 

Inch. 

Square. 

Hexagon. 

1 

1 

1,951 
812 
428 
248 
165 

3,020 
800 
444 
261 
165 

1 
« 

n 
ii 

109 
81 
65 
34 

100 
83 
62 
31 

Weight  in  Lbs.  of  Nuts  and  Bolt  Heads. 


Head  anil 
Nut. 

Diameter  of  Bolt  in  Inches. 

i 

•017 
•021 

\ 

\ 

1 

i 

•43 

i  '553 

1 

1 

1-1 
1-31 

H 

2-14 
2-56 

9 

3-77 
4-42 

U 

5-62 
7-00 

2 

21 

3 

H  exagon 
Square, 

•057 
•070 

•128 
•104 

•267 
•£21 

73 

•882 

8-75 
10-5 

17-2 
21-0 

28-8 
36-4 

BOLTS,    NUTS,    AND    WASHERS. 


103 


Weight  of  Wrought  Iron  Hexagon  Bolt  Heads  and  Nuts. 
(Another  Rule.) 


inch  =  -017  Ibs. 

„      =  '059   „ 

„      =  '137    „ 

=  "267 


inch  =    -461  Ibs. 

,.      -    '73  „ 

„      =  1-09  „ 

=2-13  „ 


U  inches  =  3-68  Ibs. 
1|     „        =5-86    „ 
2  =8-74    „ 


Weight  of  Washers  per  100. 
§  inch  =  If  Ibs.        f  inch  =    6|  Ibs.         1£  inch 

=  H  ',',       i    ,','    -  io|  "        ii    ',i 

Strength  of  bolts — allow  a  factor  of  safety  of  8. 


=  18|  Ibs. 
=  24      „ 
-30 


Strength  of  Bolts.     (Unwin.) 


Diameter  of 
Bolt. 

Strength  when 
there  is  no 
stress  due  to 
screwing  up. 

Pull  on 
Spanner. 

Stress  due  to 
screwing  up. 

Effective 
Strength  when 
screwed  up 
against  an 
Elastic  Flange. 

Inches. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

i 

1,008 

16 

1,312 

— 

1,886 

18 

1,476 

360 

| 

2,736 

20 

1.640 

1,096 

1 

3,798 

23 

15890 

1,908 

I 

4,986 

25 

2,050 

2,936 

U 

6,273 

27 

2,214 

4,069 

if 

8,046 

29 

2,380 

5,66-6 

1| 

10,044 

32 

2,624 

7,420 

n 

11,700 

34 

2,790 

8,910 

if 

15,750 

39 

3,200 

12,510 

2 

20,790 

43 

3,530 

17,260 

2£ 

27,180 

47 

3,940 

23',240 

2i 

33,570 

52 

4,260 

29,310 

2f 

41,760 

57 

4,670 

37,090 

3 

48,870 

61 

5,000 

43,870 

sj 

58,590 

65 

5,350 

53,240 

*l 

68,310 

70 

5,740 

62,570 

Sf 

79,740 

74 

6,100 

73,640 

4 

90,090 

79 

6,500 

93,590 

5 

136,080 

97 

7,950 

128,130 

6 

212,760 

115 

9.450 

203,310 

10* 


GAS    ENGINEERS    POCKET-BOOK. 


Proportion  of  Riveted  Joints, 

Single  Lap  Joints.      Iron  Plates  and  Rivets,  and  Steel  Plates  and 

Rivets. 


Thickness  of 

Diameter  of  Rivets. 

Pitch  of  Rivets. 

Centre  of  Rivets  to 
Edge  of  Plates. 

Plates 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Inch. 

Inch. 

Inch. 

Inches. 

Inches. 

Inch. 

Inch. 

A 

1 

u 

1 

li 
1| 

it 

i1 

1 
1* 

I 

i 

fl 

1« 

*5 

1» 

H 

f 

F 

£ 
tt 

2 
2 

2 
2 

i* 
1* 

if 

fe 

1 

1 

Ji 

2* 

*| 

}I 

1 

i 

lA 

2* 

2* 

i* 

if 

F 

it 

1* 

1* 

2| 
24 

2£ 
2& 

if 
** 

Double  Lap  Joints.     Iron  Plates  and  Rivets,  and  Steel  Plates  and 
Rivets. 


Distance  between  rows 

Thick- 
ness 
of 

Diameter  of 
Rivets. 

Pitch  of 
Rivets. 

Centre  of 
Rivets  to  edge 
of  Plates. 

of  Rivets. 

Zigzag. 

Chain. 

Plates. 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel 

Iron. 

Steel. 

Iron. 

Steel. 

In. 

In. 

In. 

Ins. 

Ins. 

In. 

In.        In. 

In. 

Ins. 

Ins. 

* 

f 

p 

2| 

2^ 

H 

ITS« 

II 

If 

2 

2* 

* 

i 

i 

2J 

2* 

H 

l| 

1J 

li 

2* 

2| 

f 

a 

i* 

3 

3J 

? 

if 

It 

H 

if 

Il9o 
1| 

il 

2| 

2| 
2| 

f 

i 
14 

5? 

3i 

3£ 

3S| 

I* 

4 
i§ 

If 

[a 

if 

2* 
*l 

2f 
2f 

1 

^ 

If 

3! 

3§ 

J  3 

i] 

2 

1H 

H 

3 

RIVETED    JOINTS. 


105 


Proportion  of  Eiveted  Joints — continued. 

Single  Kiveted  Double-butt  Joints.     Iron  Plates  and  Rivets,  and 
Steel  Plates  and  Eivets. 


Thickness 
of 

Diameter  of 
Rivets. 

Pitch  of  Rivets. 

Centre  of  Rivets 
to  Edge  of 
Plate. 

Thickness  of 
Butt  Strap. 

Plates 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Inch. 

Inch. 

Inch. 

Inches. 

Inches. 

Inch. 

Inch. 

Inch. 

Inch. 

f 

f 

ti 

li| 

ll| 

i 

l^L 

i 

i 

4 

u 

f 

2$ 

24 

14 

H 

i 

\ 

1 

8 

2^ 

2^ 

H 

H 

T'S 

4 

1 

il 

S 

O3 

2! 

i* 

if 

| 

j 

1 

I* 

14 

1 

2f 
2f 

if 
14 

14 

if 

4 
4 

I 

f 

H 

B« 

3 

12 

4 

Double  Riveted   Double-butt  Joints.     Iron  Plates  and  Rivets. 
Steel  Plates  and  Eivets. 


M    OJ 

Diameter 

Pitch 

Centre  of 
Rivets  to 

Distance  between  Rows 
of  Rivets. 

Tliickness 

IS 

of  Rivets. 

of  Rivets. 

Edge  of 
Plates. 

Butt  Strap. 

Zigzag. 

Chain. 

So 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

Iron. 

Steel. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

9 
10 

s 

P 

84 

3* 

14 

14 

If 

If 

2 

24 

f 

f 

i 

I 

14 

If 

U 

2^ 

24 

f 

4 

y 

j 

i| 

3i| 

3  ii 

14 

If 

If 

1.1 

2f 

4 

i 

i 
i 

if 

14 

If 

4 

If 

ii 

2 

2 
24 

2f 
2| 

2§ 

4 
4 

f 

i 

14 

14 

54 

H 

If 

n 

2£ 

2f 

3 

f 

f 

Kiveted  Joints. — Ultimate  resistance  to  shearing 

=  22  tons  per  square  inch  of  rivets  if  wrought  iron. 
=  30  to  40  tons  per  square  inch  of  rivets  if  steel. 
Bolts. — Heads  should  be  at  least  •?  times  the  diameter  of  screwed 
ends  of  bolts. 

Nuts. — Should  be  at  least  -83  times  the  diameter  of  screwed  ends 
of  bolts. 

Table  of  Ultimate  Single  Strength  of  Eivets. 


Diameter. 

Tons. 

Diameter. 

Tons. 

Diameter. 

Tons. 

J  inch 

•246 

|  inch 

6-16 

1£  inch 

20 

4      " 

•986 

t    ,, 

8-88 

H   „ 

24-6 

1}      » 

2-22 

1   „ 

12-1 

If   ,, 

29-8 

i     „ 

3-94 

1      „ 

15-8 

106 


GAS  ENGINEER'S  POCKET-BOOK. 


If  the  rivet  is  in  double  shear  it  will  have  double  the  strength 
shown  in  table,  i.e. 

If  a  butt  joint  has  two  cover  plates — one  each  side. 


Weight  of  Rivet  Heads  (actual). 
Two  1-inch  rivets  (heads  only)  =  9f  ounces 

»»          8        »  "  "  ~        f  " 


-^  2 


Weight  of  Rivet  Heads. 
No.  10  rivet  heads,  1  inch  diameter  =  2'7  Ibs. 

7  _    O.O 

»  »»  8          »  »  —  ^  ^      ,, 

£  _   -i  .e 

»J  ?>  4  »>  )>  *       U 

-0-9 


(W.I.G.) 


Diameter  of  Rivets  for  Plates  of  Different  Thicknesses. 


Thickness  of 
Plates  =  t. 

Diameter  of  Rivets  =  d. 

Diar.  of  Rivets  after 
Riveting  =  r04d. 

Inches. 

Inches. 

i 

0-60 

A 

0-624 

t 

0-67 

p 

0-72 

0-73 

0-78 

1 

0-79 

H 

0-85 

0-85 

1 

0-91 

T5 

0-90 

l 

0-91 

0-95 

tf 

0-97 

I 
f 

1-04 
1-12 

it 

1-10 
1-17 

1 

1-20 

14 

1-24 

Resistance  to  Shearing. 

When  rivets  fit  the  holes  exactly,  shearing  stress  =  P  —  area  of 
cross-section. 

If  the  section  is  rectangular,  and  pressure  perpendicular  to  one 

3  H 
side,  =  ^- 

If  the  section  is  circular  or  elliptical,  and  pressure  perpendicular 

4-  P 
to  one  side,  =  _ 

3  a 
If  the  section  is  square,  and  pressure  acts  parallel  to  a  diagonal, 

=  ^. 

8   a 


STRENGTH    OF    RIVETED    JOINTS. 


107 


Resistance  to  Torsion. 

12  x  33,000  x  HP. 
Twisting  moment  = 

2  ir  N 

Resistance  to  twisting  =  Shearing  stress  x  Z^ 
Z,   for  cylindrical  bars  =  0*196  d3 

b 

Z,     ,    hollow  do.    do.  =  0-196  d^~d^ 
t  di 

Zt    „    square  bars          =  0-208  side3 

Average  Proportions  of  Rivets  to  Diameter  of  Hole. 
The  shearing  resistance  of  steel  rivets  is  little  greater  than  of  rivet 
iron,  owing  to  its  necessary  soft  quality. 


Small  rivets  for  plates  less  than  f  inch  thick  may  be  riveted  cold. 
Strength  of  Riveted  Joints  to  Plates. 


Joint. 

Riveting. 

Cover  Straps. 

Pitch  of  Rivets. 
Diameters. 

Strength  of 
Joint  to  Plate. 

Lap 
Butt 

»» 
Lap 
Butt 

Single 

)> 

Double 

1 

2 

1 
2 

3d 

3d 

5-5<2 

•55 
•55 
•57 
•69 
•69 
•72 

Shearing  resistance  of  iron  or  steel  bars  =  |ths  their  tenacity. 
Rivet  iron,  shearing  resistance,  in  Ibs.,  per  square  inch      49,(>00 
„      steel        „  „  „  „  „  52,800 

Values  of  Riveted  Joints  and  Apparent  Tenacity  in  Lbs.  per 
Square  Inch. 


Iron 

Plates. 

Steel 
Plates. 

Plates 

Steel 
Plates. 

Single  riveted,    drilled   . 
„            „         punched 
Double       .,         drilled  . 
„            ..         punched 
Treble         „          drilled  . 

0-88 
0-77 
0-95 
0-85 

1-00 
0-90 
1-06 
1-00 
1-08 

40,500 
35,400 
43,700 
39,000 
45,000 

62,000 
55,800 
65,700 
62,000 
67,000 

lakmg  iron  at  46,000  Ibs.  per  square  inch,  and  steel  at  62,000  Ibs. 


108  GAS  ENGINEER'S  POCKET-BOOK. 

Apparent  Shearing  Resistance  of  Rivets  in  Riveted  Joints. 
(Unwin.) 

Iron  rivets  in  punched  holes  . . .  46,000  Ibs.  per  square  inch. 

„      drilled        .,  ...  43,000       „            „        ., 

Steel         „      punched     .,  ...  53,000       „ 

„      drilled        „  ...  49,000       „            „        '„ 

Proportions  of  Rivets.— The  height  of  a  finished  snap-head  should 
be  from  fths  to  fths  the  diameter  of  shank.  Allowance  in  length 
necessary  for  this  =  1|  times  the  diameter  ;  in  machine  riveting  add 
|th  to  £th  more.  Allowance  for  countersunk  riveting  =  diameter  of 
shank. 

Strength  of  double  riveted  joint  =  70  per  cent. 

„        „   single        „          „      =  56        „  (Herring.) 

Diameter  of  rivets  in  plates  under  £  inch  thick  should  be  twice 
the  thickness  of  the  plate. 

Diameter  of  rivets  in  plates  above  £  inch  thick  should  be  1^  times 
the  thickness  of  the  plate. 

Proportion' of  rivets  to  thickness  of  plate  diameter  =  1-2  *J  thickness 
of  plate.  (Unwin.) 

Advantage  of  machine  riveting  is  that  the  rivet  is  still  hot  when 
the  head  is  finished. 

Pressure  on  rivets  by  machine  =  about  25  tons. 

Holes  in  iron  should  be  punched,  and  afterward  drilled  out  |th  inch 
larger  to  prevent  starring  and  damage  to  the  surrounding  metal,  or 
drilled  full  size — in  all  girder  work. 

Kivets  are  not  considered  reliable  in  tension. 

The  best  way  with  steel  plates  is  to  anneal  them  after  punching  if  of 
£  inch  to  f  inch  thickness,  or  the  holes  rimered  after  punching.  Above 
this  thickness  all  plates  should  be  drilled. 

The  sharp  square  edge  of  a  drilled  hole  is  not  likely  to  add 
any  strength  to  the  rivet,  but  rather  the  reverse. 

If  the  plates  through  which  a  rivet  is  to  be  passed  are  more  than 
6  inches  in  all  it  is  distinctly  better  to  use  bolts. 

The  old  plan  of  driving  a  conical  drift  into  the  rivet  holes  is  an 
objectionable  method  of  ensuring  agreement,  as  it  injures  the  plates, 
but  if  the  holes  are  rimered  when  in  position  the  punched  hole  is 
improved  in  strength. 

With  very  soft,  ductile  plates,  it  is  believed  that  the  injury  done  in 
punching  is  comparatively  small  if  the  punch  be  sharp.  But  with 
rigid  plates  the  injury  is  apparently  serious,  the  plates  being 
weakened  15  per  cent,  to  30  per  cent.  (Unwin.) 

To  fill  up  the  hole  and  form  a  head,  from  1'3  to  T7  times  the 
diameter  should  be  allowed  in  ordinary  riveting,  and  about  three- 
fourths  the  diameter  if  countersunk  rivets  are  to  be  used. 

Machine  riveted  work  is  slightly  stronger  than  hand  work. 


STRENGTH  OF  ROPES  AND  CHAIKS. 


109 


"S  »• 

O   C3 

HN  «;<t           -'D           -IN                          -** 

i-HrHNIMCO^iOtOCJS-^O 

CHAINS. 

Breaking 
Strain  in 
Tons. 

1        1        I      (M     t-     01     ip     b-             >p                      «^ 

1    oicco^^o^^o 

| 

gS 

-If  -If  -  ?l 

C^l     CO     "^     CO     GO     O     £"5     lO     GO     "^     O     lO     O 
i—  irHrHi—  IC^CO-^^O 

IN 

rH      rH      rH 

w 

410         03 

coj^ji    ^           ^ic^ 
rH<M-*iQt-O>(NiOQO(N«OCOC5 
rH      rH      rH      (N      (N      CO      CO 

1 

S 

sjf* 

j 

Igs 

rH     rH     C^     C^l     CO     "^     U5      tr^     QO     O^     C^l      1C 

rH      rH 

ill 

rH      rH      rH      rH      C^     C^      C^      C^      CO      CO      CO      "HH      ''H 

II 

rr:fc^li±IM 

w 
1 

tSli 

<MlOOt~COrHrHN»OCOt-«OO 

i 

lj?J1 

rHrHlfq«4^«i5«baS<>l«5JH 

_g 

-*)            -*»            HN            HN 
rH     rH     C^     C^     CO     CO     ^H     ^      *O     ^O     b*     GO     Oi 

110  GAS  ENGINEER'S  POCKET-BOOK. 

Strength  and  Weight  of  Hemp  and  Wire  Bopes. 


TARRED  ITALIAN  HEMP. 
HAWSER  LAID. 

WIRE  ROPE. 
HAWSER  LAID. 

Circum- 
ference. 

B.  W. 

Weight  of  One 
Fathom. 

Iron 
B.  W. 

Steel 
B.  W. 

Weight  of  One 
Fathom. 

Inches. 

Tons. 

Lbs. 

Tons. 

Tons. 

Lbs. 

i 

•11 

•15 

I 

•17 

•221 

1 

•30 

•3 

1-0 

— 

•94 

H 

•89 

•43 

1-35 

— 

1-5 

li 

•94 

•57 

2-15 

6-25 

2-5 

2 

1-44 

•93 

4-0 

11-2 

3-5 

2i 



— 

5-0 

— 

4-5 

8 

2'16 

1-5 

6-0 

19-5 

5-75 

2f 

— 

— 

7-73 

— 

6-5 

3 

3-0 

2-02 

9-2 

24-5 

7-5 

3i 

__ 



10-93 

27-5 

8-5 

s* 

4-2 

2-9 

12-5 

45-0 

10-75 

5-6 

•3-8 

15-75 

54-5 

13-25 

4* 

6-75 

4-7 

21-0 

66-87 

17-75 

5 

8-0 

6-0 

24-8 

— 

21-5 

5J 

11-0 

7-1 

30-0 

83-0 

26-5 

6 

14-25 

8-5 

36-2 

100-0 

31-5 

6* 

16-1 

10-0 

42-75 

— 

40-6 

20-6 

11-7 

48-35 

— 

42-5 

7| 

21-75 

13-3 

55-0 

— 

46-75 

8 

25-75 

15-0 

59-0 

— 

51-75 

8J 

28-0 

17-0 

65-33 

— 

58-42 

9 

30-5 

19-0 

w 

33-75 

21-3 

10 

36-0 

23-6 

10i 

38-9 

26-0 

11 

42-0 

28-5 

11* 

45-1 

30-0 

12 

48-5 

34-0 

STRENGTH   OF   ROPES   AND    CHAINS. 
Round  Ropes  of  Iron  and  Steel  Wire.     (R.  A.  Rule.) 


Ill 


\v  ,  ;  ™i»  f 

IRON  WIRE. 

STEEL  WIRE. 

Circum- 
ference in 
Inches. 

weignt 
per  Fathom 
in  Ibs.  , 

Safe  Load 
in 

Breaking 
Load  in 

Safe  Load 
in 

Breaking 
Load  in 

Tons. 

Tons. 

Tons. 

Tons. 

1 

1 

0-33 

i-o 

0-83 

2-5 

li 

1-5 

0-58 

1-75 

1-25 

3-75 

4 

2 

0-7 

2-1 

2' 

6 

2 

4 

1-25 

3-75 

3;33 

10 

2* 

6 

1-86 

5-6 

5-33 

16 

3 

8 

2-95 

8-85 

8- 

24 

3* 

11-5 

3-88 

11-65 

10-66 

32 

4 

15-5 

4-92 

14-75 

13-33 

40 

*i 

19 

6-55 

19-65 

17- 

51 

5 

23 

7-73 

23-2 

21- 

63 

5i 

28 

9-36 

28-1 

25-33 

76 

6 

34 

11-32 

33-95 

30-. 

90 

6J 

40 

13-3 

40-0 

35-33 

106 

7 

46 

15-1 

45-3 

41 

123 

Steel  wire  ropes  are  usually  made  from  f  to  g  inch  diameter,  but  can 
be  had  up  to  3  inches  diameter.  When  made  with  a  hempen  core  they 
are  more  pliable,  and  for  that  reason  more  generally  adopted  for  the 
purpose  of  transmitting  power,  when  the  wire  rope  takes  the  place  of 
the  leather  straps  which  are  more  usually  employed.  One  advantage 
of  the  use  of  rope  gearing  is  the  greater  distance  over  which  the  power 
can  be  transmitted. 

In  testing  steel  cables,  the  result  will  only  equal  about  75  per 
cent,  of  the  aggregate  strength  of  the  individual  wires. 

Safe  working  strain  in  tons  of  iron  chains  = 
(diameter  in  eighths  of  inches)8 
10 

Weight  in  Ibs.  per  fathom  of  iron  chain  =  (diameter  in  eighths  of 
inches)2 

Safe  working  strains  in  tons  of  rope  =  circumference' 


Weight  in  Ibs.  per  fathom  of  tarred  rope  = 

White  rope  is  about  ^  lighter. 


8 
circumference* 


Safe  Working  Loads  in  Iron  Chains. 


Diameter, 
inch 


Load. 
Tons.    Cwts. 

0 
14 
16 
0 
10 


Diameter. 
1  inch 


7 


Load. 
Tons.    Cwts. 
0 


I) 

11 
13 


112 


GAS  ENGINEER'S  POCKET-BOOK. 


Approximate  Strength  of  Chains. 

The  square  of  the  diameter  in  eighths  =  the  weight  of  chain  in  Ibs. 
per  fathom. 

The  square  of  the  diameter  in  eighths  divided  by  2  =  breaking 
weight  in  tons.  Safe  load  =  J.  (F.  Rogers.) 

Temperature  of  iron  when  welding.— 1,500  to  1,600°  F. 


Strains  in  Ropes  round  Pulleys.     (R.  A.  Tests.) 
Two  treble  blocks  used.    Weight  lifted  =  59  cwt.  109  Ibs. 


Position  where  Strain  is 
taken. 

Strain. 

Holding  after 
Lowering. 

Raising. 

Lowering. 

Free  End. 

15-37 

5-91 

6-62 

1st  return 
2nd    „ 
3rd     „ 
4th     „ 
5th     „ 
6th     „ 

13-28 
12-0 
10-67 
9-7 
8-7 
6-105 

7-10 
8-42 
9-42 
10-56 
12-28 
13-56 

7-84 
8-84 
9-60 
10-56 
11-77 
12-0 

Total,  excluding  free 
end 

60-45 

61-34 

60-61 

The  free  end  has  no  share  in  supporting  the  weight. 

When  a  weight  is  being  raised,  the  strain  on  the  running  end  is 
greatest,  the  sum  of  all  the  friction  being  at  that  end,  and  on  the 
standing  end  least.  When  the  weight  is  being  lowered  the  reverse 
is  the  case. 

Safe  Working  Loads  on  Hemp  Hopes. 


Circumference. 

Load.           * 

Circumference.                Load. 

1  inch  = 

If  cwt. 

5*  inches  =  2  tons  14  cw 

li  »     = 

4       „ 

6 

=  3      „       4 

2     „      = 

7       „ 

H 

=  3      „     IBi 

2i   ,,      = 

11       ,, 

7 

=  4 

?i 

3     ,,      - 

16       „ 

ft 

=  5 

0 

Si  „      - 

21     „ 

8 

=  5 

14 

4     „      = 

28*     „ 

8* 

=  6 

7 

4*   „      = 

36       „ 

9 

=  7 

1 

5     „      = 

44*     „ 

• 

Testing  Iron  and  Steel,— If  a  fracture  of  iron  gives  long,  silky 
fibres  of  a  leaden  grey  hue,  the  fibres  cohering  and  twisting  together 


TESTING    IRON.  113 

before  breaking,  it  may  be  considered  a  tough  soft  iron.  A  medium, 
even  grain  mixed  with  fibres  is  a  good  sign.  A  short  blackish  fibre 
indicates  badly-refined  iron.  A  very  fine  grain  denotes  a  hard,  steely 
iron,  apt  to  be  cold-short  and  hard  to  work  with  a  file.  Coarse 
grain,  with  brilliant  crystallised  fracture,  and  yellow  or  brown  spots, 
denotes  a  brittle  iron,  cold-short,  working  easily  when  heated.  This 
iron  welds  easily.  Cracks  on  the  edge  of  bars  are  a  sign  of  hot-short 
iron.  Good  iron  is  readily  heated  soft  under  the  hammer,  and 
throws  out  but  few  sparks.  Nitric  acid  will  produce  a  black  spot  on 
steel ;  the  darker  the  spot  the  harder  the  steel.  Iron,  on  the  contrary, 
remains  bright  if  touched  with  nitric  acid.  Good  steel  in  its  soft 
state  has  a  curved  fracture  and  a  uniform  grey  lustre  ;  in  its  hard 
state,  a  dull,  silvery,  uniform  white.  Cracks,  thread,  or  sparkling 
particles  denote  bad  quality.  Good  steel  will  not  bear  a  white  heat 
without  falling  to  pieces,  and  will  crumble  under  the  hammer  at  a 
bright  red  heat,  while  at  a  middling  heat  it  may  be  drawn  out  under 
the  hammer  to  a  fine  point.  ("  Journal  of  Gas  Lighting.") 

Contraction  at  point  of  fracture  should  be  about  10  per  cent,  for 
plates,  15  per  cent,  for  T  and  L  iron,  and  20  per  cent,  for  round  or 
square  bars.  (Kirkaldy.) 

Iron  or  steel  subjected  to  stresses  above  half  their  ultimate  strength 
are  permanently  disabled. 

Breaking  strength  equals  39  (1  +  C.2)  tons  per  square  inch  (C.  = 
per  cent,  of  carbon).  (Bauschinger.) 

In  calculating  the  weight  of  metals  up  to  100°  C.,  the  temperature 
can  be  omitted  as  the  difference  is  so  small  (USQO).  An  iron  rod 
one  square  inch  in  section  exerts  a  force  of  one  ton  by  contraction 
in  decreasing  in  temperature  9°  C. 

Wrought  iron  increases  10fr00  of  its  length  for  every  ton  per  square 
inch  of  tension  up  to  the  limit  of  elasticity.  (Unwin.) 

The  expansion  due  to  a  tension  of  one  ton  per  square  inch  is  pro- 
duced by  a  rise  in  temperature  of  from  12°  to  15°  F.,  according  to 
the  quality  of  the  iron.  Wrought  iron  expands  by  heat  f^th  more  than 
cast  iron,  while  tension  causes  twice  as  much  stretch  in  cast  iron  as  in 
wrought  iron  when  within  the  elastic  limit. 

27°  F.  increase  or  decrease  of  temperature  causes  an  expansion 
or  contraction,  equals  a  stress  of  one  ton  per  square  inch,  if  the  metal 
be  fixed  at  each  end. 

Strength  of  wrought  iron  and  steel  increases  with  a  rise  of 
temperature  up  to  about  500°  F.,  beyond  which  point  the  metals 
become  plastic  and  will  flow  under  almost  any  strain.  (Professor 
11.  C.  Carpenter.) 

The  tensile  strength  of  steel  diminishes  as  the  temperature  increases 
from  zero  until  a  maximum  is  reached  between  200°  and  300°  F. ; 
the  total  decrease  being  about  4,000  Ibs.  per  square  inch  in  the  softer 
steels,  and  from  6,000  Ibs.  to  8,000  Ibs.  in  steels  of  over  80,000  Ibs. 
tensile  strength.  From  this  minimum  the  strength  increases  up  to 
400°  to  650°  F.  ;  the  maximum  being  reached  earlier  in  the  harder 
steels,  and  the  increase  amounting  to  from  10,000  Ibs.  to  20,000  Ibs. 
per  square  inch  above  the  minimum  strength  at  from  200°  to 
300°  F.  (J.  E.  Howard.) 

GE.  T 


114 


GAS    ENGINEERS    POCKET-BOOK. 


Effect  of  Temperature  on  the  Strength  of  Steel  and  Wrought 
Iron. 

Taking  the  initial  temperature  at  0°  C.,  with  an  increase  of  tempera- 
ture of  200°  C.,  the  strength  of  wrought  iron  is  reduced  5  per  cent. 


At    300°  Cent.  10  per  cent. 
„     400      „        27       „ 
500  62 


At    600°  Cent.   81  per  cent. 
.,     800       „        89       „ 
„  1,000      „        96       „ 


The  ratios  between  cast  iron,  wrought  iron,  and  steel  are  13'34, 
10,  and  10*7  respectively. 


Diminution  of  Strength  of  Copper  hy  Heat.      (Franklin  Institute.) 


Temperature  above 

Diminution  of 

Temperature  above 

Diminution  of 

32  degrees. 

Strength. 

32  degrees. 

Strength. 

Degrees. 

Degrees. 

90 

0-0175 

660 

0-3425 

180 

0-0540 

769 

0'4389 

270 

0-0926 

812 

0-4944 

360 

0-1513 

880 

0-5581 

450 

0-2046 

984 

0-6691 

460 

0-2133 

1000 

0-6741 

513 

0-2446 

1200 

0-8861 

529 

0-2558 

1300 

1-0000 

Weight  of  Cast  Iron  Pipes.     (See  also  page  286.) 

In  Ibs.  per  lineal  foot.     The  weight  of  two  flanges  or  one  socket  may 
be  reckoned  weight  of  1  foot : — 


THICKNESS  OF  METAL. 

t 

a 

t 

{ 

1 

1 

1| 

H 

Inches. 

2 

8-7 

12-3 

16-1 

3 

12-4 

17-1 

22-2 

4 

16-1 

22-1 

28-3 

5 

19-8 

26-9 

34-4 

42-3 

6 

2B-4 

31-9 

40-6 

49-7 

7 

27-1 

36-8 

46-7 

56-8 

8 

30-8 

41-6 

52-8 

64-3 

9 

34-4 

46-0 

58-9 

71-7 

10 

— 

fl-4 

65-1 

79-0 

93-3 

CAST    IRON    PIPES. 


115 


Weight  of  Cast  Iron  Pipes — (continued'). 

In  Ibs.  per  lineal  foot.     The  weight  of  two  flanges  or  one  socket 
may  be  reckoned  weight  of  1  foot :— 


THICKNESS  OF  METAL. 

Bore 

1 

i 

1 

1 

i 

l 

H 

li 

Inches. 

11 

56-4 

71-0 

86-4 

101-8 

12 





77-3 

93-7 

110-4 

127-4 

14 





89-6 

108-4 

127-5 

147-0 

15 







115-7 

136-1 

156-8 

16 







123-1 

144-7 

166-6 

18 







137-9 

161-8 

186-2 

20 









178-9 

205-8 

260-3 

22 







— 

— 

225-4 

284-8 

24 

— 

— 

— 

— 

— 

245-0 

309-3 

All  cast  iron  pipes  above  6  inches  diameter  should  be  cast  on  end, 
spigot  up,  and  about  4  or  6  inches  cut  off  afterwards  in  a  lathe  to 
remove  the  spongy  portion. 


Eule  for  the  Weight  of  Pipes.     (Molesworth.) 

D  =  outside  diameter  of  pipes  in  inches. 

d  =  inside 

iv  =  weight  of  a  lineal  foot  of  pipe  in  Ibs. 

w  =  It,  (D2  -  da). 

k  =  2-45  for  cast  iron  =  2-64  for  wrought  iron  =  2-82  for  brass 
=  3-03  for  copper  =  3'86  for  lead. 


116  GAS  ENGINEER'S  POCKET-BOOK. 

Ordinary  Stock  Dimensions  of  Spigot  and  Faucet  Connections. 

The  thickness  of  Metal  is  in  proportion  to  Pipes. 
SHORT  BEND. 


Diameter. 

2  in. 

3  in. 

4  in. 

5  in. 

6  in. 

Tin. 

Sin. 

9  in. 

10  in. 

12  in. 

A 

9 

m 

HI 

13{ 

14* 

1*| 

18* 

16} 

m 

J3 

B 

12 

u 

16 

17* 

1«* 

1»* 

20U 

22 

221 

2*« 

R 

Si 

H 

9 

10 

HI 

11 

12 

13 

13 

13* 

LONG  BEND. 


Diameter. 

2  in. 

Sin. 

4  in. 

5  in. 

Gin. 

Tin. 

8  in. 

9  in. 

10  in. 

12  in. 

A 

6* 

6T3« 

7 

7* 

8* 

H 

12fi 

1*1 

12| 

14* 

B 

Hi 

13 

H| 

17* 

ttf 

19| 

19f 

21* 

2»| 

25i 

B 

2| 

H 

4 

*J 

3 

H 

«I»e 

84 

Si 

*0i 

|TH  BEND. 


Diameter. 

2  in. 

Sin. 

4  in. 

5  in. 

6  in. 

Tin. 

8  in. 

9  in. 

10  in. 

12  in. 

A 

71 

9 

10* 

10* 

10* 

10* 

m 

13ft 

16* 

in 

B 

9 

10| 

11 

lit 

12ft 

13* 

in 

21  1 

19 

1C) 

II 

15.} 

lf| 

WI 

in 

17| 

16ft 

20| 

2*| 

3RJ 

24J 

Average  Weights  of  Connections. 


Internal 
Diameter. 

Tees. 

Collars. 

Syphons. 

Caps. 

Cwts.  Qrs.  Lbs. 

Cwts.  Qrs.  Lbs. 

Cwts.  Qrs.  Lbs. 

Cwts.  Qrs.  Lbs. 

2 

0      1     17 

0      0     12 

2      0     14 

009 

:? 

0      2     11 

0      0     25 

2      0     25 

0      0     1(5 

4 

039 

015 

2      1       4 

0      0     21 

5 

1      1       0 

0      1     22 

4      0     14 

0      1       2 

6 

120 

020 

4      1       7 

0      1     13 

7 

1      3    21 

0      2     20 

4      1     25 

0      1     21 

8 

2      1     21 

037 

427 

023 

9 

2      3     14 

ion 

4      2     14 

0      2     24 

10 

3      2     11 

1      0     14 

4      3    25 

035 

12 

427 

127 

610 

1      0     14 

14 

637 

200 

707 

1       1     25 

15 

7      0     18 

210 

707 

137 

16 

8      1       7 

2      2     14 

7      2    25 

1      3     14 

18 

9      1     21 

3      0    14 

11      1       0 

2      1     11 

20 

10      1     14 

314 

12      2     14 

2      1     25 

24 

16      3       0 

500 

13      0      0 

3      1       7 

SOCKET    BENDS. 


117 


Bend. 


118  GAS  ENGINEER'S  POCKET-BOOK. 

Ordinary  Stock  Dimensions  of  Flanged  Connections. 


D 

lu. 
H 

In. 
2 

In. 
2* 

In. 

3 

In. 
3i 

In. 
4 

In. 

H 

In. 
5 

In. 

6 

d     

2* 

2« 

3i3« 

3| 

•il5e 

H 

5£ 

5| 

6fl 

F 

6 

6£ 

7 

H 

8i 

9 

10 

10* 

12 

H    

9 

10 

11 

12 

12i 

121 

14 

16* 

18| 

R 

6 

5& 

6 

6| 

11 

H 

10| 

10 

»tt 

No.  of  Holes  in  Flange 

4 

4 

4 

4 

4 

4 

4 

4 

6 

Centres  of  Holes     .     . 

In. 
*i 

In. 

** 

In. 

6* 

In. 

5! 

In. 

6| 

In. 

7 

In. 

8 

In. 

8J 

In. 
10 

D 

In. 
1* 

In. 
2 

In. 
2* 

In. 
3 

In. 

3i 

In. 
4 

In. 
4* 

In. 
5 

In. 
6 

d,     

n 

2tt 

3i3« 

3^ 

*4 

4£ 

5| 

5£ 

6tf 

F 

6 

6i 

7 

n 

8i 

9 

10 

10i 

12 

L     

81 

9| 

91 

10* 

11 

HA 

HI 

12* 

12i 

R 

15 

16| 

H* 

18i 

161 

16* 

16i 

18* 

13i 

No.  of  Holes  in  Flange 

4 

4 

4 

4 

4 

4 

4 

4 

6 

Centres  of  Holes     .     . 

In. 
H 

In. 

4| 

In. 
H 

In. 
5! 

In. 
6^ 

In. 

7 

In. 

8 

In. 

8i 

In. 
10 

D 

In. 
H 

In. 

2 

In. 
2i 

In. 
3 

In. 

3i 

In. 
4 

In. 

H 

In. 
5 

In. 

6 

d     

2* 

2^ 

3i35 

3! 

H 

*f 

5f 

6 

6tf 

F 

6 

6£ 

7 

7^ 

8* 

9 

10 

10* 

12 

A     

7& 

7tf 

9* 

9^ 

9£ 

9£ 

10 

12A 

12J 

B 

7f 

6J 

9i 

[5 

9i35 

9i 

10 

12* 

12} 

No.  of  Holes  in  Flange 

-4 

4 

4 

4 

^ 

4 

4 

4 

6 

Centres  of  Holes     .     . 

In. 
4i 

In. 

*f 

In. 

6* 

1  In. 
B| 

In. 
64 

In. 

7 

In. 

8 

In. 
8* 

In. 
10 

FLANGED    CONNECTIONS. 


119 


u  - 


120 


GAS    ENGINEER  S    POCKET-BOOK. 


Diagram  showing  Weight  of  small  Cast  Iron  Pipes  of  different 
Diameters  and  Thicknesses. 


1 60 


xi" 


2"        3"        4"        5"        6"        7"        8"        9"      10"      n"       12" 
Bore. 


WEIGHT    OF    CAST    IRON    PIPES. 


121 


Diagram  showing  Weight  of  Cast  Iron  Pipes  of  different 
Diameters  and  Thicknesses. 


20'  30 

Diameters. 


40"  48" 


122 


GAS  ENGINEER'S  POCKET-BOOK. 


Weight  of  Cast  Iron  Gas  Pipes. 


Internal 
Diameter. 

Thick- 
ness  of 
Metal. 

Internal 
Diameter. 

Thick- 
ness of 
Metal. 

Inches. 

Inches. 

Cwts.    Qrs.   Lbs. 

Inches. 

Inches. 

Cwts.    Qrs.    Lbs. 

(1 

& 

0          1          3 

14 

4 

730 

jl 

0          1          7 

15 

I 

8         1         0 

2 

A 

0         1        16 

16 

f 

910 

2* 

2 

028 

j 

18 

i 

11         1         0 

f  3 

i 

0        3       18 

1 

20 

f 

13         2        0 

4 

si 

1         1       13 

21 

i 

14        0         0 

& 

5 

1 

138 

•—  i  ^ 

22 

15         0         0 

rt 

6 

IS 

2         1       15 

24 

9 

17         2         0 

1- 

7 

ft 

2         3       15 

30 

i 

26         1         0 

8 

33 

3         1       24 

Cs 

36 

i| 

34         3         0 

1 

9 

4         0      10 

42 

46         2        0 

o 

10 

1 

426 

48 

1_3_ 

51         0         0 

12 

1 

5        2      20 

Proportions  of  Pipe  Flanges,     (Unwin.) 

Thickness  of  flange  =  f  thickness  of  pipe  (  =  0 
If  joint  is  made  with  lead  ring,  thickness  =  1  1 
Width  of  flange  outside  pipe  =  twice  diameter  of  bolt  +  1 


bdt 


Diameter  of  bolts  =  0-01  6  diam.  of  pipe  x 
Number  of  bolts  =  2  +  diameter  of  pipe 

Diameter  of  bolt  hole  =  diameter  of  bolt  +  £ 

BarfFs  process  protects  iron  by  forming  on  its  surface  a  coating  of 
magnetic  or  black  oxide  of  iron,  by  subjecting  the  iron  for  some  time 
to  the  action  of  superheated  steam  at  a  high  temperature. 

Dr.  Angus  Smith's  process  consists  of  heating  the  iron  to  310°  F. 
and  plunging  it  in  a  bath  of  pitch  maintained  at  a  temperature  of  at 
least  210°.  A  little  oil  may  be  added  to  the  pitch.  Tar  with  a 
little  tallow  and  resin  forms  a  good  coating  to  be  applied  cold. 

The  requisites  of  a  good  paint  for  the  preservation  of  iron  and  steel 
are  stated  by  Mr.  Woodruff  Jones  to  be  these  :  (1)  It  should  firmly 
adhere  to  the  surface  and  not  chip  or  peel  off;  (2)  It  must  not 
corrode  the  iron,  otherwise  the  remedy  may  only  aggravate  the 
disease  ;  (3)  It  must  form  a  surface  hard  enough  to  resist  frictional 
influences,  yet  elastic  enough  to  conform  to  the  expansion  and  con- 
traction of  the  metal  by  heat  and  cold  ;  (4)  It  must  be  impervious  to, 
and  unaffected  by,  moisture  and  atmospheric  and  other  influences  to 
which  it  may  be  exposed. 


LEAD    PIPES. 


123 


A  Coating  for  Cast  Iron  Pipes. 

A  bath  made  up  of  gas  tar,  Burgundy  pitch,  oil  and  resin,  is  kept  at 
400°  F.,  and  the  pipes  are  laid  in  this  until  they  are  of  the  same 
heat  as  the  bath,  when  they  are  set  up  on  end  to  drain  off. 


Weight  of  Lead  Pipe  per  Foot  Run. 


Diameter. 

Light. 

Middling,  i 

Strong. 

Diameter 

Light. 

Middling. 

Strong 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

^  in.  pipe 

1 

1 

H 

2£  in.  pipe 

6 

8§ 

in 

2         » 

1 

11 

2 

2|     „           : 

— 

10 

1 

y 

I 

3 

4 

3     „      , 

3i  „      , 

10 
U£ 

12 
13 

13 

15 

H 

2* 

4 

H 

4     „      , 

14 

16 

17 

If 

3 

4 

5 

4i  ,,      , 

14 

17 

22 

if 

5 

7 

8 

5     „      , 

15 

22 

25 

2 

5 

6 

8 

5£  „      , 

— 

22 

2i 

8* 

11 

6     „      , 

22 

A  Table  Showing  the  Weight  of  Lead  Pipes  per  Length  in  Lbs. 


Bore. 

Length. 

Common. 

Middling. 

Strong. 

Inches. 

Feet. 

Lbs. 

Lbs. 

Lbs. 

4 

15 

16 

I 

15 

24 

27 

30 

1 

15 

30 

40 

43 

H 

12 

36 

44 

53 

H 

12 

48 

56 

67 

2 

10 

56 

70 

83 

g 

10 

70 

89 

100 

Weight  of  Composite  Pipe  per  Yard. 


inch  inside  diameter 


Lbs.  Ozs. 


13 

0 
fj 

lo 
2 
4 
4 

12 


Usual  Length 

of  Coil. 
.     50  yds. 
.     50    „ 
.     50    „ 
.     50    „ 

•  50    „ 
.     40    „ 

•  30    „ 
.     25    „ 

20    „ 


124  GAS  ENGINEER'S  POCKET-BOOK. 

Weight  of  Block  Tin  Tubes  per  Yard. 

|  inch  inside  diameter 


I 


Lbs.  Ozs. 
0     8 
0     91 
0  11" 

0  14 

1  1 


inch  inside  diameter 


2  inches  diameter 

2|    „ 
3 


Weight  of  Copper  Pipes. 

Per  foot. 
.     .     1|  Ibs.     4  inches  diameter  . 


Lbs.  Ozs. 
.     1     7 
.     1  14 
.     2     6 
.     2  15 


Per  foot 
3  Ibs. 


Soldering  Tin. 

Flux  may  be  resin  and  sweet  oil,  spirits  of  salts  (hydrochloric 
acid),  killed  with  zinc  cuttings,  or  Baker's  mixture. 

Solder.— Two  parts  tin,  1  lead,  melts  at  340°  F. 
Blow  Pipe  Solder. — 1£  parts  tin,  1  lead. 

Flux. — Dissolve  zinc  in  hydrochloric  acid  until  effervescence 
ceases  ;  filter  the  liquid,  add  i  spirits  of  sal-ammoniac,  and  dilute 
with  rain  water. 

Flux.—  One  part  lactic  acid,  1  part  glycerine,  8  parts  water. 
These  two  fluxes  will  not  rust  iron  or  steel. 

Weight  of  Black  Sheet  Iron  and  Boiled  Brass. 


Wire 
Gauge. 

Per  Sheet, 
72  x  24  in. 

Per  Sheet, 
72  x  30  in. 

Per  Sheet, 
72  x  36  in. 

P  r 
sq.  foot. 

Sl:eet  Brass, 
per  sq.  foot. 

Nos. 

Qrs.    Lbs. 

Qrs.    Lbs. 

Qrs.    Lbs. 

Lbs. 

Lbs. 

10 

2       14 

3          4 

3       21 

6* 

5f 

11 

2         '4 

2        19 

3         6 

5 

Bi 

12 

1       26 

2       12 

2       25 

H 

4 

13 

1       20 

2         4 

2       16 

4 

4i 

14 

1       13 

1       23 

2         5 

3| 

3| 

15 

1         8 

1       17 

26 

3 

3i 

16 

1         2 

1       10 

17 

22 

2f 

17 

0       27 

1         6 

13 

H 

*l 

18 

0       24 

1         2 

8 

2 

21- 

19 

0       21 

0      26 

3 

1} 

If 

20 

0       18 

0      23 

0       27 

« 

}i 

21 

0       16 

0      21 

0       25 

11 

if 

22 

0       15 

0      19 

0       23 

H 

H 

23 

0       14 

0       17 

0       20 

H 

i 

24 

0       12 

0       15 

0       18 

1 

15  oz. 

•25 

0  .     11 

0       13 

0       16 

14  oz. 

14  oz. 

20 

0       10 

0       12 

()       14 

13  oz. 

12  oz. 

SCREW    THREADS. 
Whit  worth' s  Screw  Threads. 


125 


Diar. 
of 
Screw. 

Diar.  at 
bottom 
ofThread. 

Area  at 
bottom 
of  Thread. 

No.  of 
Threads 
per  In. 

Width  of 
Nuts  across 
Flats. 

Depth 
of  Bolt 
Head. 

Diar. 
ofBolt 
Head. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

'nches 

i 

•0929 

•006 

40 

•338 

A-j-JL  F 

JL  +  JL 

i 

f 

•1341 
•1859 

•0141 
•0271 

24 
20 

•448 
•525 

f  +  t* 

4+4 

f 

4 

•2413 

•0457 

18 

•6014 

^-  +  JL  p 

i-  +  i 

•2949 

•0883 

16 

•7094 

il  +  JL  p 

JL  +  JL 

I 

4 

•346 

•0940 

14 

•8204 

1S  +  JL  B 

|» 

tt 

i 

•3932 

•1214 

12 

•9191 

|-fJL  B 

w 

4 

•4557 

•1626 

12 

1-011 

1  +  JL  B 

i 

s 

•5085 

•2027 

11 

1-101 

1  A  F 

1 

11 

•571 

•2565 

11 

1-2011 

IA  +  JL  B 

^-j-JL 

H 

F 

•6219 

•3037 

10 

1-3012 

11.  +  JL  F 

1+4 

14 

ii 

•6844 

•3687 

10 

139 

l|-f  _JL  B 

ll 

i 

•7327 

•4026 

9 

1-4788 

iJL-i-A  B 

f  +— 

15 

•7952 

•4966 

9 

1-5745 

lfg  +  i  B 

13  F 

14 

I*" 

•8399 

•5540 

8 

1-6701 

1|  +  A  B 

8 

U 

H 

•942 

•6969 

7 

1-8605 

113-J--3.   p 

8+4 

if 

4 

1-067 

•8941 

7 

2-0483 

2A  p 

2i 

it 

•1615 

1-0592 

6 

2-2146 

2A  +  JL  B 

]  A  +  J_ 

H 

•2865 

1-2999 

6 

2-4134 

2f  +  -V  F 

IA 

2! 

if 

•3688 

14715 

5 

2-5763 

2A  +  JL  B 

1  1  +  -  - 

if 

•49 

1-7525 

5 

2-7578 

2|  P 

}!+f 

2I 

if 

•5904 

1-9865 

41 

3-0183 

3j*-  F 

2 

•7154 

2-311 

41 

3-1491 

3i  +  4-  B 

11 

3— 

2£ 

•8404 

2-6602 

41 

3-337 

3A  +  JL  B 

31 

1-9298 

2-9249 

4 

3-546 

31  +  A  B 

iii-i-  j_ 

3| 

2f 

2-0548 

3-3161 

4 

3-75 

3f 

2  ig  +  -1- 

2* 

2-1798 

3-7318 

4 

3-894 

31  +  J&  F 

2A 

3f 

2f 

2-3048 

4-1721 

4 

4-049 

4-3-  F 

2^  +  ~3j 

3J 

2f 

2-384 

4-4637 

31 

4-181 

4JLB 

2!+f2 

4 

2i 

2-509 

4-9441 

3J 

4-3456 

4-5-  4-  JL  F 

4A 

38 

2-634 

5-4490 

3  2 

4-531 

4£  +  JL  B 

2f 

4| 

3* 

2-884 

6-5325 

3i 

3£ 

3-106 

7-5769 

H 

3f 

3-356 

8-8457 

3 

3-574 

10-032 

3 

4- 

3-824 

11-481 

?1 

H 

4-055 

12-914 

4 

4f 

4-305 

14-556 

2f 

5 

4-534 

16-145 

2f 

5£ 

4-764 

17-826 

2f 

5£ 

5-014 

19-745 

2f 

5f 

5-238 

21-548 

2! 

6 

5-488 

23-654 

2* 

126  GAS  ENGINEER'S  POCKET-BOOK. 

Wrought  Iron  Bolts  (Whitworth  Thread). 


Diar.  of 

Screw. 

Safe  Working  Load,  allowing  a  Stress  4,000  to  10,000  Ibs. 

Inches. 

4,000. 

5,000. 

6,000. 

7,000. 

8,000. 

9,000. 

10,000. 

£ 

26 

33 

.  40 

46 

53 

60 

67 

ft 

56 

70 

84 

98 

112 

126 

141 

i 

108 

135 

162 

189 

216 

243 

271 

182 

228 

279 

319 

365 

411 

457 

.| 

253 

347 

409 

478 

546 

614 

683 

& 

376 

470 

564 

658 

752 

846 

940 

* 

485 

607 

728 

849 

971 

1,092 

1,214 

& 

650 

813 

975 

1,138 

1,300 

1,463 

1,626 

r 

818 

1,013 

1,216 

1,418 

1,621 

1,824 

2,027 

a 

1,026 

1,282 

1,539 

1,795 

2,052 

2,308 

2,565 

t 

1,214 

1,518 

1,822 

2,125 

2,429 

2,733 

3,037 

1,474 

1,843 

2,212 

2,580 

2,949 

3,318 

3,687 

1,660 

2,013 

2,415 

2,818 

3,220 

3,623 

4,026 

if 

1,986 

2,483 

2,979 

3,476 

3,972 

4,469 

4,966 

i 

2,216 

2,770 

3,324 

3,878 

4,432 

4,986 

5,540 

H 

2,787 

3,484 

4,181 

4,878 

5,575 

6,271 

6,969 

ii 

3,576 

4,470 

5,364 

6,258 

7,152 

8,046 

8,941 

ij 

4,236 

5,296 

6,355 

7.414 

8,473 

9,532 

10,592 

H 

5,199 

6,499 

7,799 

9,099 

10,399 

11,699 

12,999 

ij 

5,886 

7,357 

8,829 

10,300 

11,772 

13,243 

14,715 

'l|: 

7,010 

8,762 

10,515 

12,267 

14,020 

15,772 

17,525 

1| 

7,946 

9,932 

11,919 

13,905 

15,892 

17,878 

19.865 

2 

9,244 

11,555 

13.866 

16,177 

18,488 

20,799 

23,110 

2* 

10,640 

13,301 

15^961 

18,621 

21,281 

23,941 

26,602 

2£ 

11,699 

14,624 

17,549 

20,474 

23,399 

26,234 

29,249 

2f 

13,264 

16,580 

19,896 

23,212 

26,528 

29,844 

33,161 

2| 

14,927 

18,659 

22,390 

26,122 

29,854 

33,586 

37,318 

2j 

16,688 

20,860 

25,032 

29,204 

33,376 

37,548 

41,721 

2| 

17,854 

22,318 

26,782 

31,245 

35,709 

40,173 

44,637 

2£ 

19,776 

24,720 

29,664 

34.608 

39,552 

44,496 

49,441 

3 

21,796 

27,245 

32,694 

38,143 

43,592 

49,041 

54,490 

3* 

26.130 

32,662 

39.195 

45,727 

52.260 

58,792 

65,325 

3£ 

30,307 

37,884 

45,461 

53,038 

60,615 

68,192 

75,769 

3f 

35,382 

44,228 

53,074 

61,918 

70,765 

79,611 

88,457 

4 

40,128 

50,160 

60,193 

70,224 

80,256 

90,288 

100,320 

4± 

45,924 

57,405 

68.886 

80,367 

91,848 

103,329 

114,810 

4£ 

51,656 

64,570 

77,484 

90,398 

103,312 

116,226 

129,140 

4f 

58,224 

72,780 

87,336 

101,892 

116,448 

131,004 

145,560 

5 

64,580 

80,725 

96,870 

113,015 

123,160 

145,305 

161,450 

•H 

71,304 

89,130 

106,956 

124,782 

142,608 

160,434 

178,260 

5J 

78,980 

98,725 

118,470 

138,215 

157,960 

177,705 

197,450 

5| 

86,192 

107,740 

129,288 

150,836 

172,384 

193,932 

215,480 

6 

94,616 

118,270 

141,924 

165,578 

189,232 

212,886 

236,540 

SCREW    THREADS. 

Whitworth's  Standard  Screw  Threads, 


127 


Outside 
Diameter 
in 
Inches. 

Diameter 
at 
bottom  of 
Thread. 

Nearest 
Size 
for 
Drilling 

Number 
of  Threads 
per  Inch. 

Outside 
Diameter 
in 
Inches. 

Diameter 
at 
bottom  of 
Thread. 

Nearest 
Size 
for 
Drilling 

Number 
of  Threads 
per  Inch. 

| 

•093 

i 

40 

ft 

•455 

y 

12 

i 

•112 

32 

* 

•508 

33 

11 

I 

•134 
•165 

& 
H 

24 
24 

1 

•571 
•622 

i 
1 

11 
10 

1 

i5g 

•186 
•241 

i 

20 

18 

if 

•684 

•732 

« 

i 

10 
9 

i 

•295 

16 

tf 

•795 

i 

9 

•346 

23 

14 

1 

•841 

i 

8 

I 

•393 

1 

12 

Hoop  Iron. 


B.  W. 

Gauge. 

Width 
in 
Inches. 

Weight 
per  Foot 
Run. 

Wei«ht 
per  100 
Foot  Run. 

B.  W. 

Gauge. 

Width 
in 
Inches. 

Weight 
per  Foot 
Run. 

Weight 
per  100 
Foot  Run. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

12 

2* 

•91 

91-78 

16 

1| 

•27 

26-52 

13 

2* 

•71 

71-23 

17 

1* 

•21 

20-84 

13 

2 

•63 

63-31 

18 

1 

•16 

16-16 

14 

If 

•48 

47-15 

19 

7 

•12 

12-37 

15 

H 

•36 

36-37 

20 

'  1 

•087 

8-84 

15 

if 

•33 

33-34 

Rust  Joint  Cement  for  Cast  Iron  Tanks  and  Cisterns. 


Cast  iron  borings  .  .  .  5  Ibs. 
Powdered  sal-ammoniac  .  1  oz. 
Flour  of  sulphur  .  .  2  ozs. 

Another  and  perhaps  better  cement  is — 


mix  with  water. 


Cast  iron  borings     . 
Powdered  sal-ammoniac 
Flour  of  sulphur     . 


6  Ibs.  ) 

1  oz.  \  mix  with  water. 


128 


GAS  ENGINEER'S  POCKET-BOOK. 


Working  Safe  Stresses  in  Ibs.  per  Square  Inch. 


Tension. 

Compression. 

Shearing. 

Cast  iron       .        f  •'•_," 

3,000 

10,400 

2,700 

Wrought  iron  bars    .     . 

10,400 

10,400 

7,800 

„           „      plates     . 

10,000 

10,000 

7,800 

Soft  steel,  untempered  . 

17,700 

17,700 

13,000 

Cast     ., 

52.000 

52,000 

38,500 

Copper          .        . 

3,600 

3,120 

2,300 

Brass         .         .         .     . 

8,600 

— 

2.700 

Gun  metal     . 

3,120 



2,400 

Phosphor  brouze  . 

9,870 

— 

7,380 

Comparative  Weights. 


Cast 
Iron. 

Bar 
Iron. 

Steel. 

Brass. 

Copper. 

Gun 
Metal. 

Lead. 

Yellow 
Pine. 

Cast  iron    = 

•953 

•925 

•807 

•83 

•8288 

•64 

16-0 

Bar  iron      = 

.048 

1 

•973 

•909 

•806 

•8087 

•67 

16-8 

Steel           = 

•076 

1-020 

1 

•933 

•89 

•8917 

•688 

17-0 

Brass            = 

•i:>3 

1-1 

1-07 

1 

•95 

•9558 

•737 

18-8 

Copper        = 

•213 

1-151 

1-123 

1-05 

1 

1-0004 

•774 

19-3 

Gun  metal  = 

•208 

1-150 

1-121 

1-046 

•99 

1 

•773 

19-0 

Lead            = 

•504 

1-5 

1-453 

1-357 

1-29 

1-292 

1 

24-0 

Yellow  pi  ne= 

— 

— 

— 

— 

— 

— 

— 

1 

Weight  of  a  Foot  Superficial  of  Parts  of  an  Inch  in  Thickness. 


£> 

i 

j. 

4 

I 

1 

1 

I 

1 

IriPh. 

Steel    .    . 

2-05 

5-1 

10-2 

15-3 

20-4 

25-5 

30-6 

35  '7 

40-8 

W.iron    . 

2-50 

5-00 

10-00- 

15-00 

20-00 

25-00 

30-00 

35-00 

40-00 

C.  iron 

2-35 

4-69 

9-37 

14-06 

18-75 

23-44 

28-12 

32-81 

37-50 

Brass    .    . 

2-84 

5-68 

11-35 

17-03 

22-70 

28-38 

34-05 

39-72 

45-40 

Copper     . 
Lead,  cast 

2-89 
3-70 

5-78 
7-39 

11-56 
14-78 

17-34 
22-17 

23-12 
29-56 

28-90 
30-95 

34-68 
44-34 

40-46 
51-73 

40-24 

59-12 

WEIGHT   OF    DIFFERENT    METALS. 


129 

Weight  per  Square  Foot  of  Various  Thicknesses  of  Different  Metals. 


30  28  26  24    Standard  Wire  Gauges. 
29  27  25  23  22  21  20  ig   18   17   16    15    14     13 


•  , 

]     | 

&    Lead. 

i 

i     i 

| 

I 

i 

, 

1 

\ 

/ 

i 

i 

1 

/ 

i  '  ' 

i 

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'  i  ' 

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Thickness  of  Metai  in  parts  of  an  inch. 


130  GAS  ENGINEER'S  POCKET-BOOK. 

Handy  rule  for  weight  of  Wrought  Iron  Plate : — 

1  superficial  foot  of  i  inch  plate  weighs  about  10  Ibs. 

Bound  Rods, 

To  find  breaking  weight  of,  square  of  diameter  in  \  inches  =  B.  W. 
diameter*  in  j  inches   =  wdght  in  ^  ^  yard 

Resistance  to  shearing  of  wrought  iron  bars,  ultimate  =  18   to 
20  tons  per  square  inch. 

Weight  of  Half-round  Iron  and  Steel  Bars. 


Breadth  in 
Inches. 

Thickness  in 
Inches. 

Sectional  Area, 
Square  Inches. 

Weight  per  Lineal  Foot. 

Iron. 

Steel. 

5 

* 

0-249 

0-83 

0-85 

H 

i 

0-273 

0-91 

0-93 

if 

i 

0-364 

1-21 

1-24 

3 

0-395 

1-32 

1-34 

it 

3 

0-451 

1-50 

1-53 

2 

S 

0-514 

1-71 

1-75 

2i 

1 

0-859 

2-86 

2-92 

2£ 

1-097 

3-66 

3-73 

Weight  of  Sheet  Brass  in  Ibs.  per  Square  Foot. 


Thickness. 

Weight 

Thickness. 

Weight 

Thickness. 

Weight 

Binn. 

in 

Binn. 

in 

Birin. 

in 

Wire 

Inches. 

Ibs. 

Wire 

Inches. 

Ibs. 

Wire 

Inches. 

Ibs. 

Gauge. 

Gauge. 

Gauge. 

No.  3 

0-259 

10-9 

No.  11 

0-120 

5-05 

No.  19 

0-042 

1-77 

»    4 

0-238 

10-0 

„  12 

0-109 

4-59 

,  20 

0-035 

1-47 

0 

0-220 

9-26 

,.  13 

0-095 

4-00 

,  21 

0-032 

1-35 

,     6 

0-203 

8-55 

.  14 

0-083 

3-49 

,  22 

0-028 

1-18 

.     7 

0-180 

7-58 

,  15 

0-072 

3-03 

,  23 

0-025 

1-05 

.     8 

0-165 

6-96 

,  16 

0-065 

2-74 

,  24 

0-022 

0-926 

,     9 

0-148 

6-23 

,  17 

0-058 

2-44 

i  25 

0-020 

0-842 

.  10 

0-134 

5-64 

,  18 

0-049 

2-06 

,  26 

0-018 

0-758 

Comparative  Strengths  of  Steel,  Wrought  Iron,  and  Cast  Iron. 
Relative  areas  required  to  withstand  a  given  strain. 

Tension.  Torsion.         Compression. 

Steel      ....     2-23  3'33  1'43 

Wrought  iron    .         .     .     4-44  5-00  5-23 

Cast  iron        .        .        .     9-45  36*00  2'45 

The  cohesive  power  of  iron  and  cement  equals  40  to  47  kilometres  per 
square  centimetre. 

Iron  embedded  in  cement  docs  not  rust. 


WEIGHT    OP    BOUND   AND    SQUARE    RODS. 


131 


Strength  of  Double-Headed  Bails  (Steel) 
Breaking  weight  at  centre  =  30  (±a  ~  +  M67  t  d*) 


a  =  area  of  one  flange  in  inches. 

d  =  depth  over  all  of  rail  in  inches. 

d"  =  vertical  distance  apart  of  centres  of  flanges. 

t    =  thickness  of  web. 

L  =  length  of  span  in  inches. 

Weight  of  Hound  and  Square  Iron  and  Steel. 


Iron. 

Steel. 

Iron  . 

Steel. 

1 

Rd. 

Sq. 

Rd. 

Sq. 

1 

Rd. 

Sq 

Rd. 

Sq. 

I 

II 

|| 

E| 

II 

I 

ii 

&! 

tt  _iJ 

S| 

a 

S3 

4»V) 

bD  c4 

II 

3>1 

S  — 

S       S^ 

VJ 

|l 

ii 

Sj 

6 

£3 

|| 

*3 

^3 

M 

H 

Ins. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Ins. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

A 

0-092 

0-117 

0-094 

0-120 

*1 

11-82 

15-05 

12-06 

15-35 

i 

0-164 

0-208 

0-167 

0213 

H 

13-25 

16-87 

13-52 

17-21 

4 

0-256 

0-326 

0-261 

0-332 

14-77 

18-80 

15-06 

19-18 

1 

0-368 

0-469 

0-376 

0-478 

2£ 

16-36 

20-83 

16-69 

21-25 

& 

0-501 

0-638 

0-511 

0-651 

2| 

18-04 

22-97 

18-40 

23-43 

I 

0-654 

0-833 

0-668 

0-849 

2f 

19-80 

25-21 

20-19 

25-71 

ft 

0-828 

1-060 

0-845 

1-076 

H 

21-64 

27-55 

22-07 

28-10 

1 

1-023 

1-302 

1-043 

1-328 

3 

23-56 

30-00 

24-Oi; 

36-60 

1-237 

1-576 

1-262 

1-607 

H 

27-65 

35-21 

28-21 

35-91 

j 

1-473 

1-875 

1-502 

1-912 

81 

32-07 

40-83 

32-71 

41-6.5 

is 

1-728 

2-201 

1-763 

2-245 

4 

36-82 

46-87 

37-55 

47--81 

* 

2-004 

2-552 

2-044 

2-603 

4 

41-89 

53-33 

42-73 

54-40 

if 

2-301 

2-930 

2-347 

2-988 

4|- 

47-29 

60-21 

48-23 

61-41 

i 

2-618 

3-333 

2-670 

3-400 

4! 

63-01 

67-50 

54-07 

68-85 

i| 

3-313 

4-219 

3-380 

4-303 

4f 

59-07 

75-21 

60-25 

76-71 

4 

4-09V 

5-208 

4-172 

5-312 

5 

65-45 

83-33 

66-76 

85-00 

i| 

4-950 

6-302 

5-049 

6-428 

5j 

72-16 

91-87 

73-60 

93-71 

i* 

5-890 

7-500 

6-008 

7-750 

5| 

79-19 

100-83 

00-78 

102-85 

6-913 

8-802 

7-051 

8-978 

5| 

86-56 

110-21 

88-29 

112-41 

if 

8-018 

10-208 

8-178 

10-412 

6 

94-25 

120-00 

96-13 

122-40 

9-204 

11-719 

9-388 

11-953 

61 

102-27 

130-21 

104-31 

132-81 

2 

10-472 

13-333 

10-681 

13-600 

e| 

110-61 

140-83 

112-82 

143-65 

K  2 


132  GAS  ENGINEER'S  POCKET-BOOK. 


NOTES   ON  WROUGHT   IRON   GIRDERS. 

Depth.— The  depth  of  girders  in  ordinary  cases  should  be  from 
^  to  Jg  of  span,  if  intended  to  serve  as  a  parapet  may  be  increased 
to  |,  in  flooring  ±. 

Weight. — The  weight  in  tons  may  be  found  approximately  by 
multiplying  the  load  to  be  carried  by  the  total  length  of  girder  and 
dividing  by  400. 

Strain. — The  safe  strain  when  not  given  may  be  assumed  at  5  tons 
in  tension  or  4  tons  in  compression  per  square  inch. 

Bearing  Surface. — The  bearing  surface  in  square  feet  may  be  found 
by  dividing  the  weight  on  abutment  by  one  of  the  following  constants 
according  to  the  material  of  abutment,  viz.  : — Granite  25,  limestone  25, 
sandstone  15,  firebrick  10,  strong  red  brick  7,  weak  red  brick  3£. 

Camber. — Half  an  inch  rise  per  10  feet  length  of  girder. 

Area  of  Flanges. — Section  of  top  or  bottom  flange  to  girder  at 
intermediate  points  from  centre. 

1.  Distributed  load. 

J, 

W  x  2 

-=; —     — -  =  Section  area  of  top  or  bottom  flange  in  centre  in 

square  inches. 

2.  d  =  distance  of  point  from  nearest  support. 

—  =  Sectional  area  of  flange  at  any  other  point  in  square 


inches. 
3.  x  =  Sectional  area  at  any  point. 

j?— ^ — — - —  =  distance  of  such  section  from  nearest  support. 

W 

Example. — A  girder  20  feet  long  carries  a  distributed  load  of  40  tons, 
and  is»2  feet  deep, 

By  (1)    40  x  10     =  10  inches  sectional  area. 
2x4x5 

By  (2)  Sectional  area  required  3  feet  from  end. 
40  x  3 


2x4x5 


=  3  inches  sectional  area.. 


By  (3)  Suppose  flange  to  be  made  of  3  plates,  each  3'3  inches 
area,  centre  section  will  be  10  inches;  section  outside  first  plate  will 
be  0-6  inches  ;  section  outside  second  plate  will  be  3*3  inches. 

10  x  2  x  4  x  5  _  1Q  feet  distance  of  section  of  10  inches  from 
support. 

feet  6  ii 
from  en< 
length  of  plate  6  feet  6  inches. 


=  6  feet  6  inches  distance  of  section  of  2  plates 
from  end  =  (20  feet  -  13  feet  2  inches)  = 


WROUGHT   IRON   GIRDERS.  133 

3-3x2x4x5  _  3  f  eet  3  incheg  digtance  of  section  of  j  plate 

40  from  end  =  (20  feet  -  6  feet  6  inches)  = 

13  feet  2  inches  length  of  second  plate. 

I 4 -  20(0' 


-•I -  20'.0' „ 

p         73.2;  ._-— .4 

jr----6.  6  ---• tj 


S«ction3-)"  Section  6  6  Section  10° 

In  rolled  joists  ith  of  the  area  of  web  may  be  included  in  each  of  the 
areas  of  the  top  and  bottom  flanges  when  calculating  the  strength  of 
the  joist. 

To  find  the  net  area  of  a  joist  in  inches — 

A  _  W  ^       .        f  -7-  5  =  inches  area  if  wrought  iron. 


To  find  W  =  distributed  load—     A  X  ^  X— 

„      „     d  =  depth  of  girder  in  feet  —  c        ~ 

L  x  W 
,,      „     a  =  net  section  in  inches —  7^ =pr 

\j    X    U 

„      „     L  =  span— 


»      »> 


I  x  \\r 

S  =  tons  strain  per  square  inch —  5 r -, 

o   X   A  X  (I 


134 


GAS    ENGINEER'S    POCKET-BOOK. 


/-s 

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p 

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When  it  is  required  to  know  the  nearest  stock  size  of  joist  for  any  load  and  span 
find  the  load  on  bottom  line,  and  note  the  vertical  line  for  this  load,  then  find  the 
span  on  left  hand  side,  follow  the  horizontal  line  opposite  the  span  until  it  cuts  the 

4-> 
CO 

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•133d    Nl    NVdS 


STRENGTH    OF    ROLLED    JOISTS. 


135 


Diagram  to  find  the  Proper  Size  of  Boiled  Iron  Joist. 
For  any  given  Distributed  Load.     (Factor  of  Safety,  |rd)— continued. 


18.7" 


•jo 


136 


GAS  ENGINEER'S  POCKET-BOOK. 


Moments  of  Inertia  and  Eesistance  of  Beams, 
Solid  Rectangle. 

BD3  _  ad2 


~T2~        12 
CBD2       Cad 


Hollow  Rectangle. 

?"'*"!!  T  _  BD3  -  l>d'3 

— "To — 


Solid  Circle. 


R  = 


=  --  =  M 


Hollow  Circle. 


Solid  Elliptical  Section. 

immMfa     \   =  -7854  BD3 
R  =  -7854  CBD2 


MOMENTS    OF    INERTIA. 
Hollow  Elliptical  Section. 

T  =  -7854  (BD3  -  B'Drr, 
R  _  -7854  C  (BD3  -  B  P'3) 


137 


One  Flange. 


I  =  |  JBD3  +  B'D'3  -  (B'  -  B)  D"3 


6D 


>.;. 


I  =     iBD3  -  (B  -  K)  (D-  C)3 
+  BD'3  -  (B'  -  K)  (Df  -  C' 


Wooden  Joists  (square  or  rectangular)  — 


"  ^^ 


0-23  a  oak 


=  Breaking  weight  in  tons  on  centre. 


Cast  iron  beams—  2d  x  area  of  bottom  flange  in  inches  _ 

L 


Area  of  top  flange  should  equal  one-third  that  of  bottom  flange. 


138  GAS  ENGINEER'S  POCKET-BOOK. 

Wrought  iron  beams  with  top  and  bottom  flange — 
6d  x  area  of  bottom  flange  in  inches  +  £th  area  of  web  _ 
~L~ 

B  and  d  in  inches,  L  in  feet.     Rivet  holes  deducted  when  calcu- 
lating area  of  web  and  flange. 
Box  girders  are  about  8  per  cent,  stronger  than  single  plate  girders. 

Relative  Strength  of  Beams  or  Girders. 

Relative 
Strength. 

Supported  at  one  end  and  loaded  at  the  other  =    1 

,,         „        „  „     load  distributed       —    2 

„        „    both  ends  „       ,,    at  centre  —    4 

„        „  „          .,       „    distributed        =    8 

Firmly  fixed  at  both  ends  and  „  „          =16 

Eule  for  Distributed  Breaking  Weight  on  Steel  Joists. 
8  x  D  x  strain  on  bottom  flange 

L 

D  =  depth. 
L  =  length. 

Strain  =  area  of  bottom  flange  -f  Jth  area  of  web  x  28  tons  per 
inch. 

Board  of  Trade  Eegulations  for  Bridges. 

Greatest  stress  per  square  inch  in  any  part  not  to  exceed  5  tons 
either  in  tension  or  compression  when  made  in  wrought  iron. 

When  of  cast  iron  the  factors  for  dead  load  are  taken  and  that 
portion  of  the  load  which  is  moving  is  doubled. 

When  of  steel  the  greatest  stress  per  square  inch  not  to  exceed 
OJ  tons. 

Fonts  et  Chausse"es  allow  3-81  tons  per  square  inch  in  wrought  iron 
girders  in  compression  or  tension. 

Cast  Iron  Girders. 
If  supported  at  both  ends  and  centre  load  W  =  — j- 

,  .,  „  distributed  load  W  ='^L 

With  distributed  load,  if  d  =  A  L,  W  =  A  4-17 
„     =AL,W  =  A5 

If  load  is  placed  on  top  flange,  area  should  =  — 

B 

If  load  is  placed  on  bottom  flange,  area  of  top  flange  should  =  -g- 
Depth  at  ends  should  =  — 


CAST    IRON    GIRDERS. 


139 


With  a  test  load  =  £  W,  safe  deflection  equals  ±  inch  per  foot  of  span 
In  the  above  W  =  breaking  weight  in  tons. 

a  =   area  of  bottom  flange  in  inches. 

d  ==  depth  of  girder  in  inches  over  both  flanges. 

L  =  span  of  girder  in  inches. 

If  the  depth  of  a  wrought  iron  plate  girder  equals  -JT  ,  then  strain  on 
top  or  bottom  flange  at  centre  in  tons  equals  distributed  load. 

If  the  depth  of  a  wrought  iron  plate  girder  equals  — ,  then  strain  on 
top  or  bottom  flange  at  centre  in  tons  equals  1£  distributed  load. 

If  the  depth  of  a  wrought  iron  plate  girder  equals  —  ,then  strain  on 
top  or  bottom  flange  at  centre  in  tons  equals  1^  distributed  load. 

Continuous  Girders. 

The  distance  of  the  point  of  contrary  flexure  from  pier,  when  the 
load  on  each  span  is  equal,  is  £  span.  When  the  load  is  greater  on 
one  span  than  the  other  the  distance  equals 

(7  load  on  first  span  -  load  on  the  other  \ 

-  x  span  I 
8  load  on  first  span  / 

The  pressure  on  the  abutments 

(7  load  on.  first  span  -  load  on  the  other  \ 
— Tfi ~  / 

/ 

The  pressure  on  centre  pier  equals  f  span  (load  on  first  span  +  load 
on  the  other). 

Thickness  of  Web  Plates  Required  to  Resist  Diagonal  Forces. 
(Chas.  Light.) 


Thickness 

Net  Unsupported  Distance  in  Inches,  whether  between  Pillars 
or  Booms. 

of  Web. 

24 

27 

30 

33 

36 

39 

42 

45 

48 

51 

Inches. 

i 

1-5 

1-2 

1-0 

•8 

'7 

•6 

•5 

•45 

•4 

•36 

A 

2'8 

2-2 

1-8 

1-5 

1-3 

1-2 

I'O 

•9 

'  '8 

4-3 

3'5 

3'0 

2'6 

2'2 

1-9 

1-7 

1-5 

1-3 

1-2 

_z_ 

6'3 

5'3 

4-5 

3-9 

3'4 

2-9 

2-6 

2'3 

2'0 

1-8 

i 

8-7 

7'4 

6-3 

5-5 

4'8 

4'2 

3-7 

3'3 

3-0 

2-7 

JL 

11-2 

9-8 

8'5 

7'4 

6'5 

5-7 

5-1 

4'6 

4-2 

3'8 

14-0 

12-3 

10-8 

9-5 

8'4 

7'5 

6-7 

6-0 

5-4 

4'9 

. 

17-0 
20-0 

15-0 
17-9 

13-4 
16-1 

11-9 
14'5 

10-6 
13-0 

9'5 
11-7 

8'5 
10-5 

7-6 
9-5 

6-8 
8-6 

6-3 
7  '8 

Tabular  numbers  show  safe  thrust  in  tons  per  foot  width  of  plate. 
Tabular  numbers  under  distance  required  must  not  be  less  than 
the  shearing  force  per  foot  of  plate. 


no 


GAS  ENGINEER'S  POCKET-BOOK. 


Limits  of  Weights.  &c,,  of  Wrought  Iron  that  can  be  used  without 
Increase  of  Cost. 


Length. 

Width. 

Area. 

Weight. 

Depth. 

Plates    .     . 
Bar  Iron    . 
L  &  T  bars  . 

Channel  or 
E.J.   .    . 

15  ft. 
30  to  35  ft. 
35  ft. 

35  ft. 

4  ft. 
flat  bars,  Gin. 
breadth    and 
depth  added 
H  .    .  Y  . 

28  sq.  ft. 

4   cwt. 
4     ,, 

4     „ 
4     „ 

7  ins. 

Transverse  Strength  of  Plates.    (Deduced  from  Rankine.) 


Plate  supported  at  2  sides,  distributed  load,  strength  = 


Square 


16W 


central 


L 

Circular,  supported  all  round,  distributed  load,  strength 
3-1416  X 


Circular,  supported  all  round,  central  load,  strength 
9-42  x  Skbd* 


If  firmly  riveted  to  an  immovable  abutment,  strength  equals  1'5 
above  strengths. 

Formula  to  obtain  Ultimate  Strength  of  Angle,  or  Tee  Iron  or  Steel 
Struts  (as  for  struts  in  roof  trusses). 

Breaking  load  in  Ibs.  per  square  inch  of  area  of  cross-section  of  pillar = 

Coefficient 
length  in  inches2 


least  radius  of  gyration2  x  K 

Coefficient  for  wroughtiron  equals  40,000.  K  =  if  both  ends  flat  or 
fixed,  36,000  to  40,000. 

Coefficient  for  cast  iron  equals  80,000.  K  =  if  both  ends  hinged, 
18,000  to  20,000. 

Coefficient  for  soft  steel  equals  52,000.  K  =  if  one  end  flat  or  fixed, 
other  hinged,  24.000  to  30.000, 


LEAST   RADIUS    OF    GYRATION.  141 

least  Eadius  of  Gyration.     (Adapted  from  "  Trautwine.") 


Equal  Angles. 


Xl     X 
X  1     X 


=  -20 


|JX  ii.  x  i—26 


lfxlfxf  =  -35 
2  x2  x^  =  '40 
2  x2  x  $  =  '38 
2£  x  2  J  x  i  =  '45 


9ix2ix  ^  =  '49 


2|x2Jxi  =  - 

2|x2fxi  = 
3  x3  x£  = 
3  x3  x£  = 


4x4x  f=  -81 
4x4  x  f=  -80 
5x5x  ^=1-00 
5x5x1  =  -98 
6x6  x  i7g=M9 
6x6x1  =1-17 


Unequal  Angles. 


3  x2 

3  x2 

3  x2J 

3  x2J 


3^x3 


=  -64 


x3 
x3 


x3 
x3 


x  f  =  '67 
x  |  =  -65 


5    x4    x    f  =  -87 
5    x4   xl   =-86 


6    x3£x  ^='82 
6    x3ixl   =-81 


6   x4    x  I76  =  '92 

6  x4    xl   =-91 

6|x4    xl10=-93 

7  x3fxl8  =  -84 


Equal  Tees. 


Unequal  Tees. 


1    xl 


-26 


l|x  l|x  J=r-37 
2    x2    xA  =  -43 


2    xl    x  i  =  ' 


3  x3    x 
3£x3i  x 

4  x4    x 


3    x  2-  x 

3  x  3^-  x 

4  x22x 


i  =  - 


4    x3    x |= 

4    x  3-  x  -  = 

4r-  x  3-^-  x  -  ~~" 

52x2|x  |  = 

O      X  4:      X  T«  =^ 


•86 
•88 
•91 

•72 
•70 


Roughly,  weight  of  wrought  iron  bridge  may  be  assumed— 
For  30  feet  spans,  single  line,  5  cwt.  per  foot  run 

60  »  »  »    6          »             »> 

100  „  „  „     9 

150  „  „  „  12 

200  „  „  „  15 

Dense  crowds  average  120  Ibs.  per  square  foot. 
For  flooring,  H  cwt.  to  2  cwt.  per  square  foot,  exclusive  of  weight 
of  flooring 


142 


GAS  ENGINEER'S  POCKET-BOOK. 


In  storehouses,  from  2  cwt.  to  4  cwt.  per  square  foot. 
Under  no  circumstances  is  a  girder  of  less  than  ^th  of  the  span 
advisable. 

Bolt  Centres  in  Angle  Irons. 


-c  -i-fl  q 

J.--IA    —  ' 

A. 

B. 

I 
'*-'• 

A. 

11 

f 

I 

3| 

2 

1* 

7 
8 

2£ 

If 

1* 

41 

3 

If 

1* 

5 

B. 


24 


c. 

If 
1* 
1* 
If 

9 


.  _  _          4^   x    area  of    web  below  centre   of  gravity 

xtoliett  I  iron     — ^ —  — 

\u 

breaking  weight. 

A  distributed  load  causes  stresses  only  one-half  as  great  as  a  centre 
load. 

A  load  at  end  of  a  projecting  beam  or  cantilever  causes  stresses 
four  times  as  great  as  a  centre  load. 

Size  of  L  Iron  laths  for  Slate  Roofs. 


Distance  Apart 
of  Principals. 

Laths  12  Inches 
Apart. 

Laths  1<H  Inches           Laths  8|  Inches 
Apart.                           Apart. 

5     0 
5     6 

1"  x   1"  x   8  w.  g. 

irxirxow.g.  j    ir  x  ir 

6     0 
6     6 

If   X  If  X   ()  W.  g. 

If  x  If  x  8w.  g. 

f        x  9  w.  g. 

7     0 

ir  x  ir  x  r 

If"  x  If"  x  Gw.g. 

ir  x  ir  xsw.g. 

Tie  Bods  should  have  end  eyes  of  the  following  proportions. 


Proportions  of  Plate,  Flanges,  and  Bolts.     (Unwin.) 

Bolt  diameter  =  d  =  |ths  thickness  of  plate  +  £th  (but  not  less 
than  |  inch). 


ARCHES.  143 

Pitch  of  bolts  about  6<7,  or  less  if  necessary  for  strength. 
Width  of  chipping  strip  equals  f  thickness  of  plate. 
Width  of  flange  equals  2d  +  f . 

Approximate  rule  for  depth  of  arches : — 

C  ^~r  =  D        C  =  coefficient  =  for  stone  '3,  brick  '4.  rubble  -45. 
/•  =  radius  of  curve. 

Minimum  thickness  of  abutments  for  arches  of  120  degrees  where 
the  depth  does  not  exceed  3  feet 


3r\2        3-r        . 
2h)     ~U  =  t 

r  equals  radius  ;  h  equals  height  of  abutment  to  spring  ;  t  equals 
thickness  of  abutment. 

The  abutments  are  assumed  to  be  without  counterforts  or  wing 
walls. 


Strength  of  Flat  Plates.     (Grashof.) 
If  supported  on  a  circular  support  and  uniformly  loaded— 

Greatest  stress  =  §  radius  of  support2  x 
0  thickness  of  plate2 

If  encastre  at  the  edge — 

radius2 

Greatest  stress  =  \  •- — x  W.  per  square  inch. 

thickness2 

If  supported  only  and  with  central  load- 
Greatest  stress  =  (-Q  log- h 

V  6  ro 

=   10        20        30        40        50 
_*    log.  -.-  +  1   =    4-07      5-00      5-53       5 -92      6'22 


If  a  rectangular  plate   is  eucastr  J  at  the  edges  and   uniformly 
loaded  — 


Greatest  stress-  1  _       -  __  x  --         x  Wper  sq.  in.  in  Ibs. 
~  2  length4  +  breadth4     thickness2 

If  a  square  plate  is  similarly  supported  and  loaded  — 

length  of  side  2 
Greatest  stress  =  %  —  .,  .  v  —  —  2  —  x  W  per  sq.  inch  in  Ibs. 

Any  arching  or  dishing  of  the  plates  increases  their  strength 
considerably. 


144 


GAS  ENGINEER'S  POCKET-BOOK. 


Moments  of  Inertia. 


Circular  section  (diameter  =  «T),  0*0491  d* 
Annular  section  (diameters  =  d1,  rf2),  0-0491  (da 
Square  section  (length  of  side  =  *),  i.s-* 
Kectangular  section  (longer  side  #,  shorter  7t),  £ 
Cross-shaped  section,  if  bending,  is  parallel  to  H, 


Cupolas  for  Melting  Iron. — Average  Sizes. 


Diameter 
of  Shell. 

Quantity  of 
Metal  Melted 
per  hour. 

Height 
about. 

Diameter 
of  Shell. 

Quantity  of 
Metal  Melted 
per  hour. 

Height 
about. 

Ft.  Ins. 

Ft.  Ins. 

Ft.    Ins. 

Ft.    Ins. 

1  10 

10  cwt. 

12  10 

3     9 

3i  tons 

20     » 

2     0 

15     „ 

13     6 

4     0 

4       „ 

22     0 

2    6 

1    ton 

15     0 

4     6 

5 

25     0 

2     9 

H     „ 

16    3 

4     9 

H 

26     0 

3     0 

2       ,, 

17    6 

5     0 

6 

28     0 

3     6 

3       " 

20     0 

Water  will  ooze  through  cast  iron  \  inch  thick  at  250  Ibs.  per 
square  inch. 

Water  is  only  compressible  rtnmth  Pai't  by  a  pressure  of  324  Ibs. 
per  square  inch,  or  22  atmospheres,  and  regains  its  bulk  on  removal 
of  the  pressure. 

Breaking  strains  on  4  in.  C.  I.  gas  pipe  at  3  ft.  bearing  =  8  tons; 
on  3  in.  pipe,  3  tons  13  cwt. ;  on  2  in.  pipe,  1  ton  5  cwts.  (Experi- 
ments Croydon  Gas  Co.) 


STACKING    COALS. 


145 


UNLOADING  MATERIAL  AND  STORAGE 

21  bushels  coke  =  1  cubic  yard. 
72        „         „      =  1  ton. 

To  measure  a  heap  of  coals,  from  40  to  43  cubic  feet  should  be 
taken  for  each  ton. 

Cannel  coal,  45  cubic  feet  per  ton. 

Mr.  Wyatt  says  2£  acres  are  required  per  1,000,000  cubic  feet  per  day. 

Coal  store  should  equal  6  weeks'  supply. 

Coal  storage,  Newbigging's  rule,  0  to  8  weeks'  maximum  make. 


Space  Occupied  per  Ton  of  Different  Coals. 


Weight  per 
Cubic  Foot. 

Welsh  anthracite 

=  39  cubic  feet      58-25  Ibs. 

„      bituminous 

=  43       ,        „        53 

» 

Lancashire 

=  44       , 

„        53 

» 

Newcastle 

=  45        , 

„         50 

if 

Scotch 

=  43 

„         53 

j> 

Navy  allowance  for  storage  =  48       .        „ 

Coke  in  bays  measures  per  chaldron  52  to  52^  cubic  feet  per 
chaldron. 

Coke  diminishes  in  weight  by  exposure  to  the  weather.  (See  also 
p.  232.) 


Average  Weight  of  Various  Coals. 


Per  Cub.  Ft. 
Solid. 

Per  Cub.  Ft 
Heaped. 

Cub.  Ft.  per 
Ton.  Heaped. 

Per  Cub.  Yd. 
Solid. 

Anthracite 
Bituminous 
Cannel 
Coal  as  stored 

85-4  Ibs. 
78-3    .. 
7i>-8    „ 

58-3  Ibs. 
49-8     „ 
48-3     ., 

38-4  c.  ft. 
45-3     „ 
40-4     „ 

2,160  Ibs. 
2,100    „ 
2,190    „ 
1,150    „ 

Coal  Stores. 

Coal  stores  in  the  open  should  be  paved  with  a  slope  to  carry  off 
rain  water. 

Ventilation  of  coal  stacks  may  be  effected  by  constructing  open 
piers  of  brickwork  or  wood,  or  inserting  perforated  pipes,  round 
which  the  coal  is  laid  ;  or  wicker  tubes. 


146  GAS  ENGINEER'S  POCKET-BOOK. 

In  designing  walls  for  coal  stores  the  object  to  be  attained  is  to 
keep  the  centre  of  gravity  of  the  mass  of  the  wall  as  much  towards 
the  inner  side  as  possible,  as  the  strength  of  a  wall  to  resist  side 
pressures  varies  as  the  distance  from  the  centre  of  gravity  to  the 
outside  edge  of  the  wall  at  the  base,  and  as  the  weight  on  the 
foundations.  On  this  account  walls  with  panels  sunk  in  are  usually 
adopted. 

There  can  be  little  or  no  assistance  from  cross  walls  inside  coal 
stores,  or  from  the  end  walls,  more  especially  when  the  walls  are 
thick,  a  necessity  where  much  coal  has  to  be  stored.  The  corners  of 
such  buildings  frequently  develop  cracks  from  top  to  bottom  of  the 
walls  nearly  vertical,  which  would  entirely  remove  any  advantage 
which  the  side  walls  might  have  otherwise  given.  Probably  the 
cause  of  these  cracks  is  the  expansion  taking  place  in  long  walls 
exposed  to  the  sun  while  the  end  walls  are  cool  and  shaded. 

Iron  ties  are  not  reliable  when  imbedded  in  the  coals,  as  when  the 
latter  heat  the  ties  extend,  and  the  tension  on  the  walls  is  relaxed  ; 
and  this  may  cause  the  wall  to  overturn  through  the  upsetting  of  the 
centre  of  gravity  of  the  wall. 

Mr.  F.  Marshall  has  designed  a  coal  store  with  the  floor  a  series  of 
inverted  pyramids,  the  sides  of  which  are  built  of  "  Monier  "  concrete 
arches,  the  bottom  points  of  the  pyramids  being  so  arranged  that  the 
coal  may  pass  out  in  a  regulated  quantity  on  to  a  conveyer,  and  by 
this  carried  to  the  retort  house. 


Stabling. 

Floor  space  required  in  stables  per  horse       .    .  120  square  feet. 

Width  of  stalls  for  horses 6  feet. 

Width  of  building  from  wall  to  wall  for  stables  1 H     ., 

Height  of  stables 12     „ 

A  horse  requires  about  30  to  40  Ibs.  food  per  day. 

Capacity  of  oat  bins  required  per  ton    .         .     .  75  cubic  feet. 

Capacity  of  hay  lofts  required  per  ton        .         .  500       „       „ 


Roads. 

A  layer  of  hydraulic  concrete  at  least  8  inches  thick,  or  a  foundation 
of  12  inches  of  gravel,  well  rammed  in,  with  1  inch  of  sand  on  top, 
should  be  laid  under  paved  roads. 

Asphalt  for  roadways  and  for  traffic  should  be  2  inches  thick  ; 
pavement  of  yards,  covering  of  roofs,  £  inch  to  1  inch  thick  ;  damp 
courses,  |  inch  to  f  inch. 

The  road  surfacing  asphalt  is  crushed,  heated  to  275°  or  300°  F., 
s^*ead  uniformly  where  wanted,  and  stamped,  rolled,  and  smoothed 
with  heated  irons. 

Coke  breeze  for  tar  paving  footpaths  best  made  by  using  water 
with  the  tar  to  ensure  the  distribution  through  the  whole  of  the 
breeze.  Twenty-four  gallons  tar  to  the  yard  of  breeze  is  sufficient. 


RESISTANCE   OF   COMMON    ROADS. 


147 


Grooves  in  Hobson's  floor  plates  are  best  filled  in  with  112  Ibs.  pitch, 
85  Ibs.  sand,  and  56  Ibs.  cement,  with  a  little  creosote  oil  on  second 
boiling  to  make  it  pliable  ;  remainder  filled  in  with  tar  concrete  and 
rendered  with  4  parts  coarse  sand  to  1  part  cement. 


Resistance  to  Traction  on  Common  Eoads.    (F.  V.  Greene.) 


.     10  Ibs.  per 

ton. 

Asphalt      .        o 

15     , 

Wood       . 
Best  stone  blocks 
Inferior  stone  blocks 
Average  cobble  stone 
Macadam 
Earth 

21 
.     41     ,,         , 

.     .    33     „        , 
.     50     .,         , 

on 

J7U         ,,                  . 

.         .         .  100     „         , 
.  200     . 

Resistance  of  Surface  of  Different  Roads. 

Stone  tramway,  exclusive  of  gravity  .         .      .     20  Ibs.  per  ton. 
Paved  roads  .,  „      .  33     „         „ 

Macadamised  roads   „  „  .        44  to  67     „        „ 

Gravel  „  „      .  150     „ 

Soft  sandy  or  gravelly  ground,  exclusive  of 

gravity 210    „ 

The  limiting  gradients  in  ordinary  roads  are — Asphalt  1  in  GO  ; 
wood,  1  in  25  ;  macadam,  1  in  20  ;  and  granite,  1  in  15  ;  but  there 
are  instances  of  macadam  roads  as  steep  as  1  in  6. 

The  average  resistance  to  traction  upon  road  tranways  is  about 
30  Ibs.  per  ton  with  a  minimum  of  15  Ibs.  and  maximum  of  60  Ibs. 
per  ton. 

Sir  G.  Molesworth  stated  (1895)  that  the  greatest  economical 
gradient  for  ordinary  locomotives  wras  1  in  40. 

To  set  out  a  curve  make  a  template  to  sketch. 


Where  A  C  =  the  chord 
B  D  =  versed  sine. 

A  pencil  held  at  B  when  the  template  is  moved  round  and  kept 
close  to  nails  at  A  and  C  will  mark  the  curve  required. 

L  2 


1 48        GAS  ENGINEER'S  POCKET  BOOK. 


Unloading  Materials. 

A  coal  store  should  be  well  roofed  in.  and  have  an  iron  floor  beddeo 
in  cement,  all  supports  passing  through  and  in  contact  with  the  coal 
should  be  of  iron  or  brick  ;  if  hollow  iron  supports  are  used  they 
should  be  made  solid  with  cement.  Under  no  conditions  must  a  steam 
or  exhaust  pipe  or  flue  be  allowed  in  or  near  any  wall  of  the  store, 
nor  must  the  store  be  within  20  feet  of  any  boiler  furnace  or  bench  of 
retorts.  (Prof.  V.  B.  Lewes  at  Soc.  Arts,  1892.) 


Tractive  Power  of  Locomotives. 

D  =  diameter  of  cylinder  in  inches. 

L  =  length  of  stroke  in  inches. 

T  =  tractive  force  on  rails  in  Ibs. 

P  =  mean  pressure  of  steam  in  cylinders  in  Ibs.  per  square  inch. 

W  =  diameter  of  driving  wheel  in  inches. 


W 

In  Permanent  Way  Work. 

Eight  yards  run  of  metals  require — 

2  lengths  rail cost  (1894)  £4  Is.  9d.  per  ton. 

8  sleepers „        „  2s.  4d.  each. 

2  pairs  fishplates        .        .         .     .     „        „  Wd.  pair. 

8  bolts  at  1  Ib.  (G  =  5  Ibs.  11  ozs.)  .     „        „  11*.  per  cwt. 

32bolts(6  =  31bs.lOozs.)         .     .     „        „  Ss.Wd.  per  cwt. 

Labour  costs,  say,  Is.  per  yard  run. 

Average  weight  of  cast  steel  crossings  (Vicker's  patent),  say  5  cwt. ; 
price,  1894,  32*.  per  cwt. 
Average  cost  of  switchrails  and  stockrails,  1894,  £5. 

Materials  acquired  per  Mile  of  First  Class   Railway. 

Steel  rails,  bull  headed,  at  85  Ibs.  per  yard  133*  tons. 

Chairs,  3,872,  at  50  Ibs 86£     „ 

Fishplates,  steel  clip,  352  pairs,  at  40  Ibs. .       fij     „ 
Bolts  and  nuts,  1,408,  at  H  Ibs..         .        .       1     ton. 

Spikes,  7,744,  at  1J  Ibs 4|  tons. 

Trenails,  solid  oak,  7,744 
Keys,  oak  .  3,872 
Sleepers,  creosoted,  1,936 

[n  relaying,  the  old  materials  may  be  credited  at  55  per  cent,  of  the 
cost  of  the  new  work 


RESISTANCE   ON    RAILWAYS.  149 

Usual  Type  of  Bail  used  on  English  railways. — The  bull  head  of  steel 
of  90  Ibs.  per  yard  of  an  average  length  of  30  feet.  Bessemer  steel  is 
most  used.  Rails  are  drilled  at  ends,  and  the  bolts  are  of  steel.  Test 
for  rails  is  one  to  three  blows  of  a  1-ton  weight  falling  from  various 
heights ;  the  rail,  placed  on  bearings  3  feet  6  inches  apart,  must  not  show 
any  signs  of  fracture  or  exceed  a  given  permanent  set ;  sometimes  a 
further  test  is  made  by  hanging  a  dead  weight  of  40  tons  in  centre  of 
3  feet  bearings,  giving  a  maximum  deflection  of  §-inch  and  no  per- 
manent set  after  one  hour's  suspension. 


Eesistance  of  Curves.     (Morrison.) 

W  =  weight  of  vehicle. 

R  =  radius  of  curve. 

F  =  coefficient  of  friction  of 'wheels  on  rails  =  '1  to  '27 

according  to  weather. 

D  =  distance  of  rails  apart  from  tread  to  tread. 
L   =  length  of  rigid  wheel  base. 

„    .  A                                       WF(D  +  L) 
Resistance  due  to  curve  = ^5 

ZK. 


Elevation  of  Outer  Rail  on  Curves. 

Width  of  gauge  in  feet  x  velocity  in  miles  per  hour2 (  eievatiOn  in 

1*25  radius  of  curve  in  feet  ~  I      inches. 

Axle  Tests  are  that  they  should  be  placed  on  solid  bearings  3  feet 
6  inches  apart,  and  subjected  to  five  blows  of  a  2,000  Ibs.  weight 
falling  20  feet,  the  axle  being  reversed  after  each.  For  wagons  the 
ultimate  tensile  resistance  should  be  35  to  40  tons  and  25  per  cent, 
elongation  in  three  inches. 


Resistance  of  Trains. 

W  =  weight  of  carriage  without  wheels  and  axles. 

10  =         „      „   wheels  and  axles. 

D  =  diameter  of  wheels  on  tread. 

d   =         „         „  journal. 

F  =  coefficient  of  axle  friction  =  say  -035  with  grease,  '018  with 

oil. 
/    =         ,,          n  rolling  friction  =  about -001. 

R   =  resistance  of  vehicle  =/  (W  4-  w)  +  (WF 


150 


GAS  ENGINEER'S  POCKET-BOOK. 


Crane  Hooks,  deduced  from  Experiments  at  London  and  North 
Western  Railway  Company's  Works. 

(Diameter  of  link  of  chain  in  Aths  of  an  inch  \  - 
g —  —  J  =  working  load  m  tons. 

6  =  diameter  of  chain. 

K  _  (  1'15  times  diameter  due  to  twice  area  of  6  up  to  10  tons. 
1  1*2  _    „          „          „    „      „        „    ,,  „  above  10  tons. 
A  =  3  X  Je  -f  C,  B  =  %  A  +  -9  C,  E  =  If  A,  D  =  A  X  '8. 
S  =A  x  J,  T  =  Ax|,  R  =  A,  M  =  C,  F  =  C. 


HYDRAULIC  CRANES.  151 


EETOET  HOUSE. 

Best  site  for  a  Gas  Works  is  the  lowest  point  to  be  served,  and,  at  the 
same  time,  close  to  the  point  of  delivery  of  the  raw  material,  such 
as  a  railway,  canal,  or  river. 

Average  consumption  per  head  2,000  cubic  feet  per  annum  in  large 
towns  ;  1,600  cubic  feet  per  annum  in  medium  sized  towns  ;  1,000 
cubic  feet  per  annum  in  small  towns. 

Area  of  ground  required  for  7,000,000  cubic  feet  per  day,  17  acres 
inclusive.  (A.  Colson.) 

Hydraulic  Power  pressure  usually  adopted  700  Ibs.per  square  inch. 

Old  Beckton  Hydraulic  Cranes,  nine  in  number,  lift  a  total  weight 
of  20  cwt.  each — designed  to  discharge  40  tons  an  hour  with  a  lift  of 
60  feet.  Two  horizontal  high  pressure  pumping  engines  equals  75  horse- 
power each,  with  17  inches  diameter  and  17  feet  stroke  accumulator 
—each  engine  would  work  the  nine  cranes  ;  but  with  a  lift  of  90  feet, 
as  afterwards  arranged,  both  engines  are  required.  Cranes  are 
multiplied  10  to  1,  lifting  chain  travelling  at  60  feet  in  10  seconds, 
and  the  ram  6  feet  in  same  time.  Even  with  90  feet  lifts  the  cranes 
can  easily  lift  40  tons  per  hour,  and  have  done  considerably  over  that 
quantity.  On  the  same  pier  are  six  steam  cranes  of  the  best  type, 
requiring  two  30  horse-power  boilers  to  keep  them  going,  whereas, 
with  hydraulic  power,  two  20  horse-power  boilers  work  one  pair  of 
pumping  engines  sufficient  to  actuate  six  cranes. 

The  practical  efficiency  of  the  distribution  of  hydraulic  power  in 
towns  may  be  taken  as  50  per  cent,  to  60  per  cent,  of  the  power 
developed  at  the  works. 

Loss  of  head  due  to  velocity  in  hydraulic  pipes 

(Gallons  per  minute)2  X  length  of  pipe  in  yards 
3  X  diameter  of  pipe  in  inches 

Friction  of  the  ram  of  an  accumulator  may  be  taken  as  2£  per  cent. 
Friction  in  steam  engine  pumping  into  accumulator  may  be  taken 
as  8-3  per  cent. 


Thickness  of  Hydraulic  Cylinders. 

d. 

Where  d  =  external  diameter  of  the  cylinder  in  inches,  D  = 
internal  diameter  of  the  same,  also  in  inches. 

Loss  of  power  by  multiplying  gear  upon  hydraulic  rams  varies  from 
7  per  cent,  when  direct  acting,  to  50  per  cent,  when  multiplying  16  to  1. 

Velocity  of  water  in  feet  per  second  =  8  V  height  of  fall  in  feet, 
where  there  is  no  deduction  from  the  force  for  friction  or  other 
resistance. 


152  GAS  ENGINEER'S  POOKET-BOOK. 

Saving  by  use  of  Conveyor  and  Priestman  Grab. 

At  a  works  using  about  49,000  tons  per  annum  _ 
Old  style  —  In  barge        4  men        6,s-.  ) 

On  run          2     „  6#.  (  per  day. 

On  crane       1  man        6*. 


7  men 
plus  wear  and  tear  of  trucks  and  run  equals  about  4d.  per  ton. 

New  style  -In  barge  1  man         4*.  5d.  } 

Conveyor  engine  1     „  3*.  9d.  V  per  day. 

Crane  1     „  4,9.  M.  \ 

3  men 

plus  wear  and  tear  of  elevator,  conveyor  engine,  fuel,  and  interest  on 
£1.200  (cost  of  elevator,  conveyor,  and  engine),  about  l-8Qd.  per  ton. 

d. 

Craneman       .        .        v.    ,    =    '45  per  ton. 
Engineman  and  bargeman      .    =     -60     „     ., 
Interest,  wear  and  tear       .     .     =     -42     „     „ 
Coke,  6  sacks  per  day,  and  oil    =    -33    .,    „ 


Average  Composition  of  Fireclays. 

Peroxide 

Silica.     Alumina,  of  Iron.     Lime.     Magnesia.     Potassa.    Titanic  Acid.    Soda. 
65-0         28-0         4-6         0'3         0'35  1-2  0.25  0'3 

Composition  of  Fireclay. 

Silica  (Si02)       .        .        .  .  59  to  96  per  cent. 

Alumina  (A1203)    .        .         .  .  2  to  36    „      „ 

Oxide  of  Iron  (Fe203)         .  2  to    5    „      ., 

Lime,  Magnesia.  Potash,  Soda  .  traces. 

The  more  alumina  that  there  is  in  proportion  to  the  silica,  the  more 
infusible  the  fireclay.     (J.  Hornby.) 


Dinas  Bricks. 

Silica 95  per  cent. 

Alumina  and  oxide  of  iron  .   2  to  3     „       „ 

Lime 1  to  2     „       ., 

These  bricks  swell  on  burning,  linear  expansion  0-9  to  3-4  per  cent., 
after  being  heated  for  14  days  to  1700°  C. 

Silica  in  ordinary  Stourbridge  firebricks  =      (55  per  cent. 

,      „          „         Welsh  „         =     95    „       „ 

Specific  heat  of  fireclay  .        .        .        .  =  0'21    „       '„ 


FIREBRICKS. 


153 


Tests  of  Firebricks  at  Royal  Arsenal. 


Cracked  At. 

Crushed  At. 

Stourbridge  . 

1,478  Ibs. 
1,156     , 

per  square  inch 

2,400  Ibs.  per  square  inch 

i     i  -  •  • 

MO<>    5>      »       »        » 
1,512    „      „       ,, 

Newcastle 
Plympton 
Dinas  .     .     . 
Kilmarnock  . 
Glenboig  .     . 

889    , 

1,689    , 
1.123     , 
2.134    , 
1,067   „ 

»       >         » 

2,666    „      „       „ 

1,288    „      „       „ 
3,378    „      .,       „ 

1,556  „   ;,    „ 

5? 

Cubes  1£  inch  sides,  cut  from  soaps,  were  used  and  placed  between 
pieces  of  sheet  lead. 

Fireclay  Blocks  Weigh  per  100. 


Inches. 

18X    9X3 
24X16X3^ 
24xl2x3i 

1 
3 
2 

8 
17 
19 

3 
1 

1 

0 
0 
0 

1  Ellis  and  Grahamsley's, 
f         Newcastle. 

12X   9X   6x3| 

1 

15 

0 

0 

}wV»1oVi 

9X   9X   6x3| 

1 

3 

0 

0 

12  X   9X   6x3| 

1 

11 

2 

1 

Mobberley  and  Perry's. 

General  Notes. 

Ewell  bricks  are  soft  and  not  suitable  for  use  where  clinker  bars- 
are  liable  to  be  used,  and  should  be  set  in  Bwell  loam. 

Dinas  firebricks  fuse  at  about  3,880°  to  3,930°  F. 

Firebricks  from  magnesia  are  being  made,  and  recommended  for 
very  high  heats,  containing  95  to  97'8  per  cent,  pure  magnesia  ;  they 
are  set  in  a  mortar  made  up  of  magnesia  powder. 

About  \  ton  of  fireclay  is  required  per  1,000  Newcastle  firebricks 
used. 

If  there  be  a  thick  joint  or  the  broken  corner  of  a  brick  where  the 
flames  from  the  furnace  can  get  a  hold  upon,  it  will  rapidly  hollow 
out  the  brickwork  at  that  point  ;  joints  should  therefore  be  very 
thin.  Fireclay  suffers  no  deterioration  of  quality  from  rain. 

Twenty-one  cubic  feet  of  dry  ground  fireclay  firmly  packed  =  1  ton ; 
\1\  cubic  feet  of  blocks  =  1  ton. 

Retorts. 

A  good  retort  will  sound  metallic  when  struck,  but  if  under-burnt 
or  unduly  cracked  will  give  a  dull  sound. 

H.  Eeissner's  Rule  (Berlin  Gas  Works),  15  per  cent,  retorts  in 
reserve  in  midwinter. 

For  machine  stoking  with  20  feet  through  retorts,  Mr.  West 
suggests  a  space  of  21  feet  6  inches  in  front  of  beds  each  side  at 
least,  and  18  feet  extra  length  from  the  centre  of  the  end  retort  to 
enable  the  machines  to  be  run  out  of  the  way. 


154  GAS  ENGINEER'S  POCKET-BOOK. 

The  lowest  point  of  the  roof  trusses  should  be  32  feet  high  from 
stage  or  floor  line,  at  11  feet  from  face  of  retort  stack. 

Height  of  tie-beam  of  roof  in  retort  house  should  be  at  least 
20  feet  above  floor  line. 

It  is  best  not  to  allow  floor  joists  in  stage  retort  houses  to  bear 
upon  the  brickwork  of  the  setting,  owing  to  the  great  expansion  and 
contraction  of  the  latter. 

Openings  in  the  roof  of  retort  houses  near  the  eaves  have  been 
objected  to  as  likely  to  drive  the  smoke  downwards. 

The  openings  in  side  walls  of  retort  houses  for  ventilation  should 
be  above  the  level  of  the  top  of  beds. 

Provide  as  few  doorways  on  floor  line  as  possible  in  retort  house. 

Concrete  under  retort  settings  should  be  at  least  1  foot  below  floor 
line. 

Space  in  front  of  benches  should  be  22  feet  or  25  feet  if  machinery 
is  to  be  used. 

It  is  likely  to  be  cheaper  to  build  the  retort  house  of  sufficient 
width  to  erect  upon  the  stages  the  ordinary  coal  hoppers  and  bins, 
from  which  the  coal  can  be  elevated  direct  to  charging  hopper  at  any 
part  of  the  machine's  progress  along  the  stage,  by  an  elevator 
attached  to  the  machine.  (A.  F.  Browne.) 

Mr.  Wyatt's  Rule— 1  foot  run  of  retort  house  per  ton  carbonised 
per  day  or  6,000  cubic  feet  with  floor  area  of  1,000  feet  per  ton  per 
day,  and  costs  18  per  cent,  of  total  capital  at  a  rate  of  ±d.  per  cubic 
foot  all  provided. 

Drain  pipes  to  stoke-holes  9  inches  diameter  best  laid  with  a  fall  of 
3  inches  in  each  100  feet  run,  with  3  feet  x  3  feet  manholes  to  about 
every  100  feet  (1  foot  9  inches  of  ground  above  the  shallowest  end). 

The  loss  of  power  in  distributing  energy  by  compressed  air  equals 
50  per  cent. 

Heat  of  one  bed  of  retorts  has  heated  a  boiler  3  feet  6  inches 
diameter  9  feet  long  after  heating  the  retorts,  but  this  heat  would 
have  been  better  utilised  if  heating  the  retorts. 

A  temperature  of  1,500°  F.  is  often  found  in  flues  of  moderate 
sized  works. 

Jointing  for  Mouthpieces  to  Clay  Retorts. — Two  parts  of  sulphate 
of  lime  mixed  with  water,  mixed  well  with  six  parts  iron  borings, 
with  solution  of  sal-ammoniac,  or  three  parts  fireclay  and  1  part  iron 
borings  (by  weight)  mixed  with  ammoniacal  liquor. 

Cross  Tie  Rods  to  Benches  should  be  capable  of  resisting  a  breaking 
strain  of  60  tons,  and  longitudinal  tie  rods  100  tons,  it  is  practically 
impossible  to  prevent  the  expansion  of  a  setting  when  first  lighted 
up,  and  the  tie  rod  nuts  should  be  only  hand  tight,  and  should  be 
slackened  if  found  necessary. 

End  Bnckstaves  for  Stage  Setting  should  be  12  inches  x  5  inches 
H  iron,  4  at  each  end,  and  tie  rods  to  same  2  inches  diameter. 

The  top  of  a  setting  should  be  well  covered  or  blanketed  to  prevent 
loss  of  heat  by  radiation. 

Division  walls  of  settings  should  be  not  less  than  18  inches  thick. 

Space  around  Retorts  should  not  be  more  than  4  inches  wide  at  any 
point  in  clay  retort  settings. 


SETTINGS.  155 

Clay  retorts  should  be  not  less  than  3  inches  thick. 

Smooth  inside  surfaces  to  retorts  assist  in  preventing  the  accumu- 
lation of  carbon  and  in  its  subsequent  removal. 

No  setting  should  be  used  until  at  least  14  days  after  completion, 
and  then  gradually  heated. 

Twenty-one  inches  X  15  inches  x  20  feet  D  retorts  will  easily 
carbonise  5£  cwt.  of  Newcastle  coals  in  6  hour  charges. 

Through  retorts  are  more  economical  than  singles. 

Circular  retorts  allow  a  large  space  above  the  charge,  and  are 
therefore  bad. 

The  use  of  Thicker  Walls  in  front  of  the  bench  has  been  advocated 
for  the  stoppage  of  the  ascension  pipe  trouble. 

Coke  is  sometimes  removed  hot  by  a  conveyor  under  the  mouth- 
pieces, and  carried  by  it  to  an  elevator  where  it  is  quenched  by  water 
from  a  perforated  pipe,  raised  and  piled  in  place,  the  elevator  being 
so  arranged  that  a  swivel  spout  at  the  top  allows  it  to  be  placed 
where  desired. 

The  Size  of  the  Mouthpiece  should  never  be  made,  in  any  direction, 
smaller  than  the  retort,  as  the  coke  can  then  be  easily  removed  with- 
out jamming ;  neglect  of  this  precaution  has  caused  the  mouthpiece 
to  be  removed  when  drawing  coke  with  machinery. 

"  Use  plenty  of  walls  to  support  retorts,  and  of  good  thickness,  the 
small  increased  quantity  of  fuel  required  to  heat  them  is  more  than 
compensated  by  the  life  of  the  retorts  and  setting  generally." 

"  The  brickwork  in  a  setting  should  only  be  sufficient  to  uphold  the 
retort,  and  to  be  of  as  small  an  area  as  possible  at  many  points  rather 
than  large  areas  at  few  points." 

Allow  25  square  inches  Air  Space  per  retort  between  fire  bars  in  open 
hearth  furnaces. 

In  ordinary  furnaces  allow  plenty  of  room  above  the  fuel  so  that 
the  CO  may  be  converted  into  C02  before  it  passes  among  the 
retorts,  say  equal  to  the  area  of  the  fuel. 

Ordinary  furnaces  evaporate  12  cubic  feet  of  water  per  24  hours. 

With  coal  in  furnaces,  more  space  in  flue  ways  required  with 
increased  supply  of  air. 

About  50  per  cent,  of  the  heat  generated  in  an  ordinary  furnace 
escapes  unused  up  the  chimney. 

Allow  about  twice  the  theoretical  quantity  of  air  to  ordinary 
furnaces,  or  some  of  the  CO  will  pass  away  without  being  converted 
into  C02 

Each  3  Ibs.  C  requires  8  Ibs.  O,  or  35  Ibs.  (460  cubic  feet)  of  atmo- 
spheric air,  for  complete  combustion. 

To  estimate  furnace  efficiency  : — 

If  T  =  temperature  of  smoke  gases,  t  =  temperature  of  air. 
o  =  specific  heat  of  a  cubic  metre  of  CO2  (=  up  to  150°  C.  =  0'4l! 
from  150°  to  200°  =  0'43,  from  200°  to  250°  =  0'44,  from  250t  to 
300°  =  0-45,  from  300°  to  350°  =  0'46),  c  =  specific  heat  of  a  cubi'j 
metre  of  0  or  N  (about  0-31),  then  the  loss  of  heat,  a»,  in  the  furnace 
for  every  kilogramme  of  carbon  burnt,  expressed  in  calories, 

is  x  =  1-854  (T  -  0  c  +  1-854  (T  -  Q  100~'*  C. 


156                    GAS  ENGINEER'S  POCKET-BOOK. 
Calorific  value  of  1  kilogramme  carbon  is  8080  calories  ; 
therefore     —  =  proportionate  heat  lost  by  fire 


1  kilogramme  carbon  forms  T854  cubic  metres  of  C0a  at  0°  C.  and 
760  minimum  pressure.     (Dr.  G.  Lunge.) 


Structural  Cost  per  Mouthpiece  of  Different  Settings. 
(W.  R.  Chester,  1894.) 

£    s.  <L 

Ordinary  settings 14    0  0  life  500  days. 

Klonne  gaseous  fired  setting         .                32    4  6  ,     300  „ 

Siemens      „           „           25     5  0  ,     104  „ 

West           „           „          „     ...         27  17  0  ,     406  „ 

Siemens- Foulis  gaseous  fired  setting          .     27  15  0  .     500  „ 

Chester                  „            „         „        .        17    0  0  ,500  „ 


Materials  Required  for  a  Regenerator  Setting  of  Nine  D  Retorts 

(13£  inches  x  20  inches  x  20  feet  loi;g,  4J  inch  walls). 
From  springing  of  furnace  arch  to  level  of  first  line  of  retorts  : — 

Stourbridge  Goods. 

9  inches  x  2£  inches  x  4£  inches  =  1010  Ewell  N.N.    1664. 

9      „      x2       „      x4i      „  =  120  9          172. 

9      „      xli      „      x4£      „  =  230 

9  ins.  x  2J  ins.  x  2£  ins.     Clubs  =  110 

Bevel  side  =  100 

Bevel  ends  =  200 

Feather  edge  =  100 

Arch  =     30 

From  level  of  first  line  of  retorts  : — 

Stourbridge  Goods. 

9  inches  =  822 

14      ..  =     16 

2      „  =  172 

li     „  =  237 

linch  =    82 

Bevel  ends  =146 

„     sides  =    62 

Clubs  =  128 

Arch  =  145 

Feather  edge  =  392 


REGENERATIVE  FURNACES.  157 

From  stage  line  :— 

Stonrbridge  Goods. 

14  inches  =      64  Ewell. 

9      „       =2212  S.S.        9"  =  460. 

3      „       =44  N.N.      9"  =  250. 

2      „       =    216  N.N.  arch  =  700. 

li     .,      =    224 

1  inch  =  110 
Clubs  =  184 

Feather  edge  =  742 
Bevel  sides  =  144 
„  ends  =  50 
Arch  =  118 

Regenerative  Furnaces. — Provide  for  a  good  depth  of  fuel. 

The  adoption  of  gaseous  firing  greatly  increases  the  lives  of  the 
retorts. 

Generator  settings  are  those  in  which  a  portion  of  the  heat  given  off 
by  the  furnace  is  utilised  to  heat  the  air.  for  secondary  supply. 

Regenerator  settings  utilise  the  heat  of  the  waste  gases  after  they 
have  left  the  setting  proper. 

Generator  furnaces  should  be  from  4  to  6  feet  deep,  and  of  com- 
paratively even  thickness,  usually  4  to  6  feet  long,  and  2  to  3  feet 
wide.  (J.  Hornby.) 

The  introduction  of  gaseous  firing  with  greatly  enlarged  combustion 
chambers  has  not  only  effected  great  economy  of  fuel,  but  has 
increased  the  durability  of  retort  settings  above  66  per  cent.,  while 
wear  and  tear  in  furnaces  has  been  reduced  in  a  far  higher'  ratio. 

Beds  of  retorts  run  two  years  continuously,  when  a  few  bricks  in  fur- 
naces, on  clinker  line,  have  to  be  cut  out  and  replaced.  (A.  F.  Browne.) 

The  yield  per  mouthpiece  has  been  increased  30  per  cent,  by  the 
introduction  of  Regenerative  furnaces. 

Allow  a  considerable  depth  of  fuel  in  generator  not  less  than  3  feet 
6  inches. 

The  simplest  arrangement  of  flues,  if  of  sufficient  length  and  area, 
is  quite  as  satisfactory  as  more  elaborate  methods. 

The  gases  in  a  retort  setting  should  be  made  to  travel  so  that  the 
heat  is  evenly  distributed  among  all  the  retorts  and  throughout  their 
length. 

It  is  equally  necessary  to  provide  a  good  system'  of  distribution  of 
heat  as  to  get  a  good  regeneration. 

Slowness  of  travel  and  opportunity  for  the  heat  to  pass  through  the 
material  separating  the  waste  gases  from  the  air  to  be  heated  is 
the  main  point  to  be  observed  in  designing  regenerative  furnaces. 

A  large  number  of  inlets  for  secondary  air  and  for  CO  from 
generator  is  advisable  in  combustion  chamber  arranged  so  that  an 
intimate  admixture  may  take  place. 

The  principal  point  to  aim  at  in  regenerator  settings  is  to  have 
an  equal  distribution  of  the  secondary  air  and  the  gas  along  the  line 


158  GAS  ENGINEER'S  POCKET-BOOK. 

of  the  setting,  so  that  combustion  may  be  taking  place  in  many  places 
instead  of  in  one  only. 

Long  passages  for  the  warming  of  secondary  air  not  necessary,  as 
dry  air  quickly  absorbs  heat  when  in  contact  with  hot  surfaces. 

The  combustion  chamber  should  be  sufficiently  large  to  prevent  any 
flames  passing  into  the  flues. 

Roomy  combustion  chambers  assist  in  equal  distribution  of  high 
heats. 

Heat  should  be  applied  at  the  bottom  of  a  retort,  where  the  coal 
lies,  rather  than  to  the  top  and  sides,  where  it  would  injure  the  Illu- 
minating Power  of  the  gas  passing  out. 

Only  a  slightly  excess  quantity  of  secondary  air  above  the  theo- 
retical suffices  to  cause  complete  combustion  of  the  gases  in  the 
combustion  chamber. 

About  one  fourth  the  available  heat  is  produced  in  the  generator  of  a 
regenerator  setting. 

It  has-been  suggested  that  the  steam  used  at  the  bottom  of  a  re- 
generative furnace  should  be  superheated  by  passing  through  pipes 
surrounding  the  ash-pit. 

Flues  should  be  built  of  best  firebricks  only,  and  made  absolutely 
tight,  all  cracks  being  repaired  immediately  noticed. 

Pressure  on  retorts  should  be  reduced  by  fixing  large-sized  mains 
and  avoiding  all  obstructions,  and,  if  necessary,  counterbalancing  the 
gasholders  in  works  where  no  exhauster  is  provided. 

Main  Flues  are  generally  450  square  inches  in  small  works,  increas- 
ing to  1,500  square  inches  in  large  works. 

Chimney  required  for  2,000,000  per  day  retort  house,  4  feet  6  inches 
square  inside  and  about  113  feet  high.  (A.  Colson.) 

Chimney  area  per  ton  of  coal  per  day  should  equal  24  square  inches. 

Another  rule  says  the  flue  and  chimney  area  should  be  from  30  to 
40  square  inches  per  ton  of  coal  carbonised  per  diem. 

The  flue  entrance  from  each  furnace  should  be  about  12  inches  square. 

One  square  inch  of  damper  space  per  mouthpiece  usually  sufficient 
if  draught  is  good. 

Good  or  bad  chimney  construction  may  cause  a  difference  of  50 
per  cent,  in  the  fuel  account. 

It  is  said  that  firebricks  will  increase  the  pull  upon  a  chimney 
33  per  cent,  over  that  where  common  red  bricks  are  in  use,  and  6G 
per  cent,  over  that  where  stonework  is  employed.  This  is  probably 
owing  to  the  excellent  non-conducting  properties  of  firebricks. 

Chimneys  from  retort  benches  need  only  be  lined  with  firebricks. 

A  draught  of  from  T90  inch  to  ig  inch  necessary  for  high  heats. 

Chimneys  to  each  bed  allow  an  easy  regulation  of  draught,  but  the 
same  effect  may  be  gained  by  the  use  of  shield  plates  or  thin  walls,  to 
direct  the  gases  in  all  cases  towards  the  chimney,  and  the  use  of  a 
damper  to  each  setting. 

Division  plates  should  also  be  fixed  at  the  entrance  to  the  chimney 
when  currents  of  gases  are  meeting  from  each  side.  In  all  cases 
avoid  collision  between  gases  going  in  different  directions.  Chimneys 
of  ample  dimensions  without  a  division  plate  have  often  proved 
inadequate  when  settings  on  each  side  have  been  alight. 


HYDRAULIC    MAINS.  159 

A  division  wall  carried  up  some  8  feet  in  the  middle  of  a  chimney 
having  flues  in  each  side  serves  to  give  the  gases  an  upward  current 
before  meeting. 

Fit  up  a  small  pipe  in  bottom  of  retort  house  chimney  to  attach  a 
pressure  gauge  to  indicate  the  vacuum  in  chimney.  Nine-tenths  equals 
moderate  draught. 

Lightning  conductors  should  be  of  copper,  %  inch  diameter,  or  in 
bands,  say  1|  inch  by  $  inch — the  latter  for  preference.  If  of  iron, 
either  1  inch  round  rods  or  in  bands  say  2  inch  by  f  inch. 

Newbigging's  rule  for  retort  house  chimneys  under  70  feet  high  equals 
1£  square  inch  area  per  lineal  foot  of  retort,  or  15  square  inches  per 
mouthpiece. 

Hydraulic  Mains. 

The  size  of  the  hydraulic  main  should  be  such  as  to  allow  of  a 
sufficiency  of  liquid  to  rise  in  the  dip  pipes  up  to  the  maximum  back 
pressure  likely  to  occur. 

It  is  absolutely  necessary  that  the  hydraulic  main  be  kept  level. 

Hydraulic  mains  should  be  large,  and  separated  as  to  water  level 
for  each  bench,  and  made  easily  cleanable. 

The  hydraulic  main  should  be  sufficiently  far  from  the  bench,  so 
that  the  heat  of  the  latter  may  not  form  pitch  in  the  former. 

Provide  plenty  of  handholes  in  hydraulic  mains  for  removal  of  tar 
and  pitch. 

The  heavy  tar  in  the  hydraulic  mains,  if  kept  long  in  contact  with 
the  gas,  is  liable  to  rob  it  of  its  lighter  hydrocarbons,  but  if  the  gas 
be  cooled  gradually  with  the  lighter  tar,  which  would  be  deposited 
by  it  between  150°  and  100°  F.,  for  a  time  the  gas  may  absorb 
some  of  the  lighter  hydrocarbons,  which,  with  rapid  cooling  and 
separation  from  the  tar,  would  be  lost,  and  in  this  way  deposition  of 
napthalene  in  mains  and  services  may  be  avoided. 

Hydraulic  mains  should  never  be  supported  from  the  brickwork  of 
the  settings,  as  the  unequal  expansion  of  the  latter  causes  them  to 
rapidly  get  out  of  level,  and  the  seals  of  the  different  dip  pipes  are 
thereby  altered.  They  can  be  supported  by  rolled  joists,  which  at 
the  same  time  form  the  tie-rods  at  top  of  the  bench,  or  upon  brackets 
upon  the  upright  buckstaves,  or  on  cast  iron  columns  in  front  of  the 
bench  division  walls.  The  hydraulic  main  is  sometimes  fixed  imme- 
diately over  the  rising  pipes,  but  it  then  becomes  subjected  to  con- 
siderable heat,  and  also  prevents  the  easy  cleaning  of  the  ascension 
pipes. 

A  perforated  plate  is  often  used  in  the  hydraulic  main  to  help  to 
separate  the  tar  by  friction. 

A  weir  arrangement  at  the  end  of  the  hydraulic  main,  which  reaches 
nearly  to  the  bottom  and  is  above  the  level  of  the  liquor  and  just  in 
front  of  the  overflow,  permits  only  the  heavier  liquid  to  run  away, 
and  consequently  the  seal  remains  a  light  one.  The  overflow  should 
be  square,  and  not  round,  so  that  the  liquid  can  easily  flow  away. 

The  thickness  of  ascension  pipes  may  be  kept  down  to  f  inch 
without  any  detriment  to  their  usefulness. 


160        GAS  ENGINEER'S  POCKET-BOOK. 

Jointing  for  Ascension  Pipes. — Slaked  lime  or  fireclay  well  pressed 
down. 

Curves  in  rising  and  arch  pipes  should  be  as  gradual  as  possible. 

Keep  all  curves  in  arch  pipes  gradual,  as  sharp  corners  produce 
stoppages. 

Ascension  pipes  should  be  at  least  8  inches  from  face  of  brickwork. 

Weight  of  6-inch  pipes  and  bends  in  ascension  dip  bridge  pipes  and 
covers  to  a  setting  of  nine  retorts  21  inches  by  15  inches  ;  hydraulic 
main  cover  9  feet  3|  inches  from  under  side  of  top  of  upper  mouth- 
piece equals  4  tons  0  cwt.  3  qrs.  9  Ibs. 

Dip  pipes  should  be  carried  to,  say,  within  3  inches  of  the  bottom  of 
hydraulic  main,  so  as  to  keep  the  liquid  agitated  at  this  portion  of 
the  main. 

If  the  dip  of  the  pipes  in  the  hydraulic  be  kept  at  f  inch,  and 
provision  made  for  a  water  seal  instead  of  a  tar  one,  most  of  the 
objections  to  dip  pipes  are  removed. 

Four  or  5  inches  of  liquid  is  quite  sufficient  in  the  bottom  of  the 
hydraulic  main,  as  then  the  whole  of  the  liquor  and  tar  is  kept 
agitated  by  the  passage  of  the  gas,  and  the  deposition  of  thick  tar 
prevented,  and  constant  cleaning  out  rendered  unnecessary. 

Dip  Pipes  with  light  seals  give  equal  results  to  anti-dip  pipes. 
(W.  A.  Yalon.) 

Mr.  Valon  has  abandoned  anti-dip  pipes  for  £-inch  seal,  which  he 
considers  better,  as,  if  the  former  were  used,  leaking  retorts  from  over- 
exhaustion  are  very  frequent. 

The  advantages  of  removing  the  dip-pipe  seals  : — Improved 
illuminating  power,  increased  yield  of  gas,  less  carbon  deposits  and 
napthalene,  better  utilisation  of  the  heats,  longer  life  of  the  retorts, 
fewer  stoppages  in  the  ascension  pipes,  &c.  (Ulysse  Andre.) 

A  mouthpiece  for  a  21-inch  by  15-inch  D  retort  weighs  about 
3  cwt.  1  qr.  9  Ibs.  (this  is  with  a  6-inch  round  hole  on  upper  side  for 
outlet  and  four  holes  for  fixing  flange  of  rising  pipe  with  bolts).  Lid, 
cross-bar  lever,  &c.  (Morton's  lids)  weigh  about  78  Ibs.  for  same 
mouthpiece. 

Joints  in  dip  and  rising  pipes  in  sockets  may  be  made  with  fireclay 
and  iron  borings  wetted  with  ammoniacal  liquor. 

Join  iron  mouthpiece  to  clay  retort  with  fireclay,  iron  borings,  and 
sal-ammoniac. 

Fireclay  and  iron  borings  wetted  with  ammoniacal  liquor  may  be 
used  on  all  socket  joints  as  \vell  as  mouthpieces. 

Foul  main  temperature  often  130°  F. 

Foul  main  area  should  equal  125  per  cent,  area  of  connections  in 
works. 

The  gas,  on  leaving  the  hydraulic  main,  should  be  allowed  to  flow 
slowly,  and  be  kept  at  a  temperature  of  about  140°  F.  in  the  collecting 
main  ;  then  the  small  proportion  of  benzol  serves  to  arrest  the 
napthalene  in  the  condensers.  (MM.  Delseaux  and  Renard.) 


HYDRAULIC    MA1X    VALVE 


161 


Hydraulic  Main  Valve. 


G  E. 


162 


GAS    ENGINEERS    POCKET-BOOK. 


Size  of  Connections  Usual  in  Gasworks. 


Make  per  Day. 

Make  per  Annum. 

___—___—  __ 

Diameter  of 
Connections. 

22,000 

4,000,000 

4  inches. 

31,000 

5,750,000 

6 

65,000 

12,000,000 

8 

115,000 

21,000,000 

10 

208,000 

38,000,000 

12 

285,000 

50,000,000 

14   . 

325,000 

60,000,000 

H 

370,000 

68,000,000 

16 

470,000 

85,000,000 

16 

580,000 

105,000,000 

18 

720,000 

130,000,000 

18 

830,000 

150,000,000 

18 

865,000 

156,000,000 

18 

900,000 

165,000,000 

20   , 

1,050,000 

190.000,000 

20 

1,100,000 

200,000,000 

20   , 

1,300,000 

240,000,000 

24 

Herr  Reissner's  Rule  (works  connections). — Mains,  velocity,  6*56 
to  9'84  feet  per  second.     For  small  mains  allow  lesser  velocity. 


CONDENSEKS.  163 


CONDENSERS. 

Wyatt's  Rule.— 136  cubic  feet  of  structure  inside  walls,  850  to 
1,000  gallons  per  diem. 

Clegg  gives  150  superficial  feet  per  1,000  feet  per  hour  when  the 
layer  of  gas  is  not  more  than  3  inches  thick. 

One  hundred  and  fifty  to  200  square  feet  condensing  surface  per 
1,000  per  hour  necessary.  (Butterfield.) 

Allow  5  square  feet  cooling  surface  with  wrought  iron  mains  per 
1,000  cubic  feet  in  air  condensers  from  the  outlet  of  hydraulic  main  to 
the  outlet  of  condenser.  (Herring.) 

Newbigging  says  10  square  feet  per  cubic  foot  per  minute. 

Editors  of  "  King's  Treatise  "  say  that,  under  ordinary  conditions, 
with  air  condensers,  a  superficial  area  equal  to  10  square  feet  per  1,000 
cubic  feet  per  day  is  required  from  the  hydraulic  main,  20  feet  of 
length  per  inch  diameter  of  this  pipe  should  be  in  the  retort  house. 

Messrs.  Dempster  and  Sons  recommend  a  surface  of  100  superficial 
feet  per  ton  oE  coal  carbonised  per  day,  but  add  that  120  feet  would 
be  better. 

Another  authority  says  a  surface  of  54  square  feet  is  ample  for 
cooling  35,000  cubic  feet  of  gas  in  24  hours,  equal  to  1  square  foot  per 
650  cubic  feet  in  24  hours. 

Atmospheric  Condensers. — The  pipes  from  the  hydraulic  main 
should  have  a  superficial  area  of  10  feet  per  1,000  cubic  feet  made 
per  diem. 

-  Area  required  for  condensation  equals  about  4  square  feet  cooling 
surface  (air)  per  gallon  of  water  yielded  per  ton. 

In  water  tube  condensers  about  2^  square  feet  of  cooling  surface  is 
allowed  per  1,000  cubic  feet. 

Beckton  Air  Condensers. — Gas  travels  at  the  rate  of  6*3  miles  per 
hour,  and  has  4  square  feet  of  exposed  surface  per  1,000  cubic  feet 
gas  made  per  diem.  Formerly  gas  travelled  at  a  greater  rate  (9  miles 
per  hour),  the  tarry  vesicles  being  broken  up  by  friction  against  the 
side  of  main. 

Herr  Reissner's  Rule. — 3-65  square  feet  of  cooling  surf  ace  per  1,000 
cubic  feet  per  24  hours  as  a  minimum.  4*56  square  feet  of  cooling 
surface  per  1,000  cubic  feet  per  24  hours  is  the  best  allowance. 

General  Notes. 

At  Rotherhithe  gasworks,  with  a  maximum  make  of  5,000,000,  the 
condensing  surface  is  6*76  square  feet  per  1.000  and  the  speed  655  feet 
per  minute,  but  the  final  removal  of  tar  is  not  effected  until  the  gas 
reaches  the  washers. 

Long  pipe  condensers,  through  which  gas  passes  rapidly,  will  break 
up  the  tarry  vesicles  by  the  friction  on  the  sides  of  the  pipes,  the 
rate  of  travel  at  Beckton  being  15  to  20  miles  per  hour.  Another 
method  is  to  pass  the  gas  three  or  four  times  through  a  series  of  fine 
orifices,  causing  it  to  impinge  on  a  plate.  This  also  breaks  up  the 
vesicles. 

M2 


164        GAS  ENGINEER'S  POCKET-BOOK. 

Another  plan  is  to  pass  the  gas  slowly  through  large  pipes  and 
gradually  cool  and  condense  the  tarry  vesicles.  Speed,  say  one  mile 
per  hour. 

It  is  said  that  slow  condensation,  say  four  or  five  miles  per  hour, 
causes  a  decrease  in  the  deposition  of  napthalene. 

With  annular  condensers  the  inner  air  pipes  should  be  fitted  with 
valves  to  regulate  the  quantity  of  air  passing  through  and  to  prevent 
undue  condensation  of  the  gas. 

Fvr.,.  ,  nf  Tpin.  Quantity  of  Heat  Lost  by  a  Square 

Unit  of  Exterior  Surface. 
tiireofGas. 


10°  F.  8  88 

20°  18  26« 

30°  29  5,353 

40°  40  8,944 

50°  53  1,3437 

(Peclet.) 

Condensation  should  be  sufficiently  complete  to  clear  the  gas  of  any 
redundant  napthalene  vapours,  but  should  not  be  carried  so  far  as 
to  take  out  the  hydrocarbons  so  necessary  for  increasing  its  illuminat- 
ing power.  Contact  of  the  gas  with  the  tar  should  be  as  limited  as 
possible,  as  this  substance  has  been  proved  incontestably  to  cause 
dissolution  of  the  light-giving  hydrocarbons. 

Gas  should  be  cooled  down  to  a  temperature  equal  to,  or  even 
below,  that  of  the  coldest  appliance  it  would  have  to  traverse  in  its 
passage  to  the  burner. 

"  The  temperature  of  the  gas  should  be  rapidly  brought  down  to 
about  60°  F."  (MM.  Delseaux  and  Renard.) 

Another  authority  says  :  —  "  Gas  should  be  cooled  very  slowly,  and 
not  below  50°  F.,  or  some  of  the  lighter  hydrocarbons  will  be 
deposited." 

If  napthalene  *n  dangerous  preponderance  is  to  be  kept  out  of  the 
gas,  good  condensation  must  be  adopted,  and  maintained  uniformly. 
It  is  possible  to  select  a  gas  coal  or  mixture  of  gas  coals  which  will 
yield  a  good  illuminating  gas  with  a  fair  minimum  of  napthalene. 
The  specific  gravity  of  the  tar  affords  a  fair  criterion  of  the  amount  of 
napthalene  present  in  the  tar. 

"  Mere  cooling  by  unobstructed  flow  through  pipes  and  chambers 
will  not  deprive  gas  of  the  whole  of  its  suspended  tar  —  its  complete 
removal  being  only  effected  by  means  of  friction."  (A.  F.  Browne.) 

"  To  prevent  tar  going  forward  to  the  scrubber,  fix  some  wooden 
discs  with  holes  of  varying  size,  according  to  the  make  of  gas,  and 
between  them  some  grids  constructed  of  1-inch  and  £-inch  bars  set 
|  inch  apart,  so  that  the  whole  of  the  gas  as  made  is  forced  through  the 
hole  in  the  disc  and  impinges  upon  the  iron  grids."  (W.  K.  Cooper.) 

At  14  inches  pressure  9.000  cubic  feet  of  gas  per  hour  will  pass 
through  a  hole  1  square  inch  area. 

So  long  as  the  temperature  of  the  tar  is  above  90°  F.  there  is  no 
fear  of  clogging  of  perforated  plates  used  for  separation  of  tar  from 


TAR  AND  LIQUOR  TANKS.  165 

liquor,  the  plates  being  said  to  increase  the  illuminating  power 
owing  to  the  retention  of  the  napthalene  vapour. 

After  the  tar  has  been  separated  from  the  gas  it  is  well  to  ensure  a 
prolonged  association  of  the  gas  with  its  aqueous  vapour,  which,  when 
later  on  condensed,  consists  of  8  or  9  oz.  liquor  containing  much 
CO 2  and  H2S. 

Tarry  vapours  are  more  easily  condensible  under  pressure. 

It  has  been  proposed  to  use  atmospheric  condensers  sufficient  for 
mid- winter  use,  and  supplement  these  in  summer  by  the  use  of  water- 
tube  condensers. 

Friction  tends  to  the  deposition  of  napthalene,  especially  at  low 
temperatures ;  therefore  anything  rough  on  inside  of  pipe  should  be 
removed  and  easy  bends  always  used  where  possible.  Small  mains 
likewise  cause  deposition  of  napthalene. 

Condenser  mains  should  have  a  fall  of  1  inch  per  9  feet  length. 

The  weight  of  wrought  iron  mains  is  only  about  one  fourth  to  one 
fifth  that  of  cast  iron  mains  of  equal  calibre,  and  they  are  quite  strong 
enough  for  use  above  ground  and  where  they  can  be  examined  for 
rusting,  &c.,  and  above  moderate  sizes  are  cheaper  than  cast  iron. 

Works  mains  may  be  made  of  wrought  iron  or  steel,  20  feet  long, 
with  L  iron  flange  joints. 

Byepasses  should  be  fixed  to  each  piece  of  apparatus  in  the  works. 

All  valves  and  blank  flanges  in  works  should  have  wells  dug  out 
around  them  with  brick  or  timber  sides,  and  timbers  laid  over  them 
with  £-inch  blocks  to  keep  them  slightly  apart. 

Cost  of  fitting  up  12-inch  pipes,  eight  tiers  high,  to  form  condensers, 
l\d.  per  yard  run  of  pipe  (1893)  ;  this  included  fixing  vertical  struts 
and  making  lead  joints. 

A  small  balanced  holder  at  outlet  of  condensers  serves  to  prevent 
any  oscillation  on  the  retorts,  and  is  especially  useful  where  more 
than  one  retort  house  is  worked  from  one  exhauster. 

Give  mains  in  works  inclination  of  from  \  inch  to  1  inch  per  pipe. 

Allow  a  fall  of  1  inch  in  9  feet  in  works  mains  containing  much  tar. 

Newcastle  coal  yields  about  12  gallons  water  per  ton. 
Derbyshire   .,        .,          „     26       ,,  „       „     „ 


TAR  TANKS— LIQUOR  TANKS. 

Tar  and  liquor  tanks  should  be  of  sufficient  capacity  to  hold 
850  gallons  per  ton  per  day  ;  or,  say,  five  or  six  weeks'  make. 

Tar  and  liquor  storage  for  2,000.000  plant,  500,000  gallons,  or 
four  weeks'  make.  (A.  Colson.) 

One  ton  coal  makes  about  28  gallons  10  ounces  liquor. 

Allow  not  less  than  space  for  six  weeks'  production  in  tar  and  liquor 
tanks. 

Tar  and  liquor  tanks  should  equal  four  to  six  weeks'  stock  as  a 
minimum.  (Herring.) 

Cover  tar  and  liquor  tanks  to  prevent  escape  of  the  ammonia 
gas,  and  danger  from  fire. 


166  GAS  ENGINEER'S  POCKET-BOOK. 

BOILERS,  ENGINES,  PUMPS,  AND  EXHAUSTERS, 
Exhauster  Plant. 

A  horse-power  (H.P.)  is  the  quantity  of  work  equivalent  to  the 
raising  of  33,000  Ibs.  through  1  foot  in  1  minute,  or  to  equivalent 
motion  against  resistance. 

This  is  the  usual  unit  by  which  the  power  of  any  steam  engine  is 
calculated. 

To  calculate  horse-power  of  any  engine  : — 

P  =  The  mean  effective  pressure  of  steam  in  Ibs.  per  square 
inch. 

A  =  The  area  of  the  piston  in  square  inches.  If  the  piston 
rod  runs  through  cylinder  its  area  should  be  deducted  ;  if 
only  on  one  side  of  piston,  half  the  area  should  be  deducted. 

L  =  Length  of  stroke  in  feet. 

N  =  Number  of  strokes  per  minute  =  revolution  per 
minute  X  2. 

H.P.  =  Horse-power  of  engine 

HP  —  PLAN 
33,000 

Nominal  horse-power  (N.  H.P.).— Ten  circular  inches  of  piston  .area 
are  usually  provided  for  each  N.H.P. 

Brake  horse-power  (B.H.P.)  is  the  actual  power  given  off  by  an 
engine  at  the  end  of  its  crank  shaft  or  rim  of  flywheel. 

Unit  of  heat,  or  British  Thermal  Unit  (B.T.U.),  is  the  amount  of 
heat  required  to  raise  1  Ib.  of  water  1°  at  39-1° 

Joule's  mechanical  equivalent  of  heat  equals  778  foot-pounds. 

To  raise  1  Ib.  of  water  1°  F.  requires  the  same  energy  as  to  lift 
1  Ib.  weight  through  a  height  of  778  feet,  or  778  Ibs.  1  foot. 

Mechanical  efficiency  of  a  steam  engine,  about  85  to  90  per  cent. 

Thermal  „  „  „          „       10  to  14 

Thermal  „  gas  „         „       18  to  23          „ 

Wyatt's  Rule. — 120  cubic  feet  of  building  to  house  boilers  and 
details,  and  floor  area  385  superficial  feet  per  ton  per  day.  Cubical 
contents  of  boilers  (net  outside  measurements)  not  less  than  5  cubic 
feet  per  ton  per  day. 

To  house  engines  and  exhausters  105  cubic  feet,  or  3  square  feet 
per  ton  per  diem. 

Herr  Reissner'g  Rule, — Exhausters,  Have  one  in  reserve  at  each 
works. 


HORSE- POWER    REQUIRED   TO    WORK    EXHAUSTERS. 

Horse  Power  Required  to  Give  24  Inches  Pressure, 

(Gwynne  &  Co.) 


ic; 


Cubic  Feet 
per  Hour. 

H.P. 

Required. 

Revolutions 
per  Minute. 

Cubic  Feet 
per  Hour. 

H.P. 

Required. 

Revolutions 
per  Minute. 

2,200 

i 

250 

63,000 

6 

75 

3,000 

\ 

250 

68,200 

7 

75 

5,300 

230 

73,500 

7 

75 

10,500 

1 

200 

78,700 

8 

75 

15,700 

2 

150 

84,000 

8 

70 

21,000 

2 

100 

94,500 

9 

70 

26,200 

3 

95 

105,000 

10 

68 

31,500 

3 

85 

126,000 

12 

63 

36,700 

4 

85 

147,000 

15 

61 

42,000 

4 

85 

160,000 

16 

60 

47,200 

5 

84 

180,000 

19 

60 

52^500 

5 

80 

210,000 

20 

60 

57,700 

6 

75 

300,000 

30 

60 

Exhausters  improve  the  yield  of  gas  about  11  per  cent,  without 
deteriorating  the  quality,  and  with  cannel  coals  the  improvement  is 
still  greater. 

Exhausters  should  work  with  a  minimum  amount  of  power,  and 
have  as  few  parts  to  get  out  of  order  as  possible,  and  at  the  same 
time  give  a  steady  pull  without  oscillation. 

Exhausters  only  pass  75  per  cent,  of  estimated  quantity  by 
measurement. 

Theoretical  Horse-Power  Required  to  pass  Gas  at  Various  Pressures 

without  any  Allowance  for  Friction  of  Exhauster. 

(Edwin  B.  Donkin,  1894.) 


Size. 

TOTAL  PRESSURE  OF  GAS  IN  INCHES  OF  WATER. 

6  In. 

9  In. 

12  In. 

15  In. 

18  In. 

20In.!24  In. 

30  In. 

36  In. 

40  In. 

50  In. 

5,000 

0-08 

0-12 

0-16 

0-19 

0-24 

0'26j  0-31 

0-39 

0-47 

0-53 

0-66 

10,000 

0-16 

0-24 

0-31 

0-39 

0-47 

0-53!  0-63 

0-79 

0-95 

1-05 

J-31 

15,000 

0-24 

0-36 

0-47 

0-58 

0-71 

0-79   0-94 

1-18 

1-42 

1-58 

1-97 

20,000 

0-31 

0-47 

0-63 

0-79 

0-95 

1-05    1-26 

1-58 

1-90 

2-10 

2-63 

25,000 

0-39 

0-59 

0-79 

0-98 

1-18 

1-31 

1-58 

1-97 

2-37 

2-63 

3-29 

30,000 

0-48 

0-71 

0-94 

1-18 

1-42 

1-57 

1-89 

2-36 

2-83 

3-15 

3-94 

40,000 

0-62 

0-94 

1-26 

1-58 

1-90 

2-10 

2-52 

3-15 

3-78 

4-21 

5-26 

50,000 

0-79;  1-18 

1-58 

1-97 

2-36 

2-63 

3-15 

3-94 

4-73 

5-25 

6-57 

60,000 

0-941  1-41 

1-89 

2-36 

2-84 

3-15 

3-79 

4-73 

5-67 

6.30 

7-89 

80,000 

1-24 

1-84 

2-52 

3-16 

3-80 

4-20!  5-04 

6-30 

7-56 

8-42 

10-5 

100,000 

1-58 

2-37 

3-16 

3-94 

4-73 

5-26   6-31 

7-89 

9-47 

10-5 

13-15 

150,000 

2-37 

3-54 

4-72 

5-90 

7-09 

7'87 

9-46 

11-8 

14-2 

15-8 

19-7 

200,000 

3-16 

4-74 

6-32 

7-88 

9-46 

10-5 

12-6 

15-8 

18-9 

21-0 

26-3 

250,000 

8-95 

5-92 

7-90 

9-85 

11-8 

13-1 

15-7 

19-7 

23-6 

26-2 

32-9 

300,000 

4-74 

7-11 

9-48 

11-8 

14-1 

15-7 

18-9 

23-6 

28-4 

31-5 

39-4 

168 


GAS  ENGINEER'S  POCKET-BOOK. 


Percentage  to  add  to  power  shown  on  previous  tables  to  ascertain 
horse-power  required  to  drive  exhausters  at  various  pressures— 

10,000  at  12  inches  pressure      .        .100  per  cent. 
20,000  .,  18      „  „        .        .     .       90     „       „ 

50,000  „  24      „  „    .  70     ,.       ., 

100,000  „  30      „  .     .       50     .,       ., 

200,000  „  36      .,  45     ., 

300,000  „  50      „  40     „ 

Sizes  of  Cylinders  of  Steazn  Eagine<s  required  to  drive  exhauster, 
allowing  25  per  cent,  to  35  per  cent,  margin  over  power  shown  by 
previous  tables. 


Size  of  Exhauster. 

20,000 

30,000 

40,000 

50,000 

80,000 

100,000,150,000 

200,000 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

In. 

Gas  pressure 
Boiler     „  40  j 

18 
diameter  4| 
stroke      4£ 

20 
6 
6 

22 
(i 
12 

24 
7 
12 

10 
14 

80 

152 

33 
12 

18 

36 
14 

18 

^ 

diameter 

— 



6 

gi 

10 

101 

12  < 

"          •'       ') 

stroke 



— 

12 

14 

14 

15 

18 

1 

diameter 







7 

gi 

10 

10 

"       1 

stroke 

— 

— 

— 

12 

14 

14 

18 

In  calculating  size  of  exhauster  required,  the  maximum  rate  of  gas 
made  per  hour  having  been  ascertained,  20  per  cent,  to  25  per  cent, 
should  be  added  to  allow  for  the  extra  flow  after  the  retorts  are 
freshly  charged,  allowing  also  for  the  difference  in  temperature 
between  gas  at  exhauster  and  at  station  meter.  Jf  a  byepass  is  used 
to  regulate  the  pressure  or  exhaust,  a  further  percentage  should  be 
added,  varying  with  the  amount  of  the  difference  of  pressure  and 
exhaust, 

In  the  best  modern  type  of  engine  and  good  boiler,  the  combined 
efficiency  is  only  14*01  per  cent,  or  ±th  of  the  heat  value  of  the  fuel 
used. 

10  per  cent,  to  20  per  cent,  can  be  saved  by  properly  applied  steam 
jackets  to  engine  cylinders.  Covers  should  also  be  steam  jacketed. 

In  the  cylinder  of  a  non-condensing  steam  engine,  with  saturated 
steam  at  60  Ibs.  pressure,  the  temperature  is  293°  F.,  and  at  100  Ibs. 
pressure  338°  F. 

Thickness  of  engine  cylinders  = 

diameter  x  pressure  of  steam  in  Ibs.  per  square  inch 
2,400  if  vertical,  or  2,000  if  horizontal 


or, 


or, 


T  = 


200 


X  1-2 


INDICATED    HORSE-POWER. 


169 


Effective  Pressure  of  Steam  upon  Piston  Surface, 

Boiler  pressure  assumed  at  100  Ibs.  per  square  inch.     Different 
rates  of  expansions. 

Effective 
Pressure. 

Steam  cut  off  at  f  of  stroke  =  90  Ibs. 


=  80 
=  69 
=  50 
=  40 


To  Calculate  the  Indicated  Horse-Power  of  a  Steam  Engine. 

Radius  of  cylinder2  equals  I.H.P.  at  42  Ibs.  mean  pressure  and  250 
feet  per  minute  piston  speed. 

Any  other  pressure  and  speed  may  be  calculated  from  above  by 
direct  proportion. 


Losses  in  Boilers,  Engines  and  Electricity  Plants. 


B.  T.  Us. 

Lost  in  ashes 135  . 

Lost  in  ra Jiation  from  boiler       .        .     .     675 
Carried  off  in  gases  of  chimney        .         .  2970  . 
Carried  off  in  auxiliary  exhaust  .         .     .     190 
Lost  in  radiation  and  leakage  main  pipes    210  . 
„  „  „          „       small      „          30 

„       engine        .     280  . 
Rejected  to  condenser          .         .         .     .  7737 

Engine  loss      .         .         .         .         .  76  . 

Generator  or  dynamo  loss    .        .         .     .       48 

Line  loss          .         .         .        .         ...     115  . 

Transformer  loss  .  .     .      52 


Percentage 
of  heat 
in  Coal. 

.      I'OO 
.     .     5-00 

.  22-00 
.     .     1-56 

.     1-40 
.     .    0-22 

.     2-08 
.     .  57-31 

.      -56 
.     .      -36 

.      -86 
•39 


Total  loss     . 
Heat  delivered  to  electric  light 

Heat  units  in  1  Ib.  coa 


12518         =          92-74 
982          =  7-26 


13500  . 


100-00 


(Deduced  from  "  Power.") 


170 


GAS  ENGINEER'S  POCKET-BOOK. 


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BOILERS. 


171 


Proportions  of  Steam  Boilers  per  Nominal  Horse-Powerc 

1  cubic  foot  water  per  hour. 

1  square  yard  of  heating  surface. 

1       „      foot  of  fire  grate  surface. 

1  cubic  yard  capacity. 

28  square  inches  of  flue  area. 

18      ..          „       .,      ,,      „    over  bridge. 

13i     „  ,,       of  chimney  area. 


L  x  D  (in  feet) 
6 


=  H. P.  nominal  of  any  boiler  approximately. 


Filiation  for  Examining  the  Data  when  Designing  a  Steam 
Boiler.     (Prof.  A.  Huet.) 


per    1  square  foot  grate  surface, 
per    boiler  heating  surface. 


Pounds  coal  burnt  per  hour  . 

Grate  surface     . 

Boiler  heating  surface  square  feet    per    pounds  water  evaporated 

per  hour. 
Pounds  water  evaporated 


Total 


.    per    pounds  coal  burnt, 
should  equal         Total 


Working  Strength  of  Solid  Wrought  Iron  and  Steel  Cylinders 
to  Resist  Internal  Pressure. 


Working  Pressure  in  Lbs. 

Working  Pressure  in  Lbs. 

Diameter. 

per  Square  Inch. 
(Excess  of  Internal  over 
External  Pressure.) 

Diameter. 

per  Square  Inch. 
(Excess  of  Internal  over 
External  Pressure.) 

Inches. 

Iron. 

Steel. 

Inches. 

Iron. 

Steel. 

12 

1,267 

1,767 

66 

230 

321 

18     ' 

845 

1,177 

72 

211 

294 

24 

633 

884 

78 

195 

272 

30 

507 

707 

84 

181 

252 

86 

422 

589 

90 

169 

235 

42 

362 

505 

96 

158 

221 

48 

317 

463 

102 

149 

208 

54 

282 

303 

108 

141 

196 

60 

253 

354 

Thickness  of  cylinders,  1  inch.    Working  stress  equals  7,600  Ibs.  per 
square  inch  for  wrought  iron,  10,600  Ibs.  per  square  inch  for  steel. 


172 


GAS   ENGINEERS   POCKET-BOOK. 


Diagram  showing  Working  Strength  of  Solid  Wrought  Iron  and  Steel 
Cylinders  to  Eesist  Internal  Pressure  per  1  inch  thick. 

(Deduced  from  Unwin.1) 


1800 

44- 

1700 
1600 

5 

B 

T 

? 

g  I5°° 

• 

1 

^  1403 

•£  130*5 

w 

1 

P 

\ 

b 

t-     1200 

o 

I 

1 

g     IIOO 

p 
*o   1000 

o 
x     900 

£ 

a   o- 

TTT 

l 

-U- 

j 

:E 

j 

a 

l 

-4- 

v 

ng  Pressure  in  Ibs.  per  Square  Ii 

8  1  8  ?  8  I 

~n 

Steel 
Iron, 

^ 

\ 

V 

\ 

i 

u 

•^ 

\ 

\"  ~ 

\ 

•^ 

^ 

-- 

^ 

^ 

"^4 

^ 

o 

s 

I(X) 

"l 

ift.           2             3             4              5              6              7              8            gft. 
Diameter. 

BOILERS.  173 

Notes  on  Lancashire  Boilers.     (M.  Longridge.) 

Abandon  6  feet  grates  if  a  shorter  length  will  burn  coal  at  16  to 
21  Ibs.  per  hour. 

Reduce  draught  as  much  as  the  fuel  will  permit. 

Obtain  and  use  dry  fuel  and  weigh  ashes  as  well  as  fuel  used. 

Stop  all  leaks  in  boiler  settings. 

Aim  to  keep  up  C02  in  chimney  to  10  or  11  per  cent. 

The  hotter  the  furnace  the  better. 

An  ordinary  furnace  requires  24  Ibs.  of  air  or  300  cubic  feet  of  air 
for  the  consumption  of  each  1  Ib.  of  coal  ;  if  a  blast  or  steam  jet  is 
used  this  may  be  reduced  to  18  Ibs.  or  220  cubic  feet. 

From  13  to  20  Ibs.  of  coal  may  be  consumed  per  square  foot  of  fire 
grate  ;  f  foot  of  fire  grate  required  to  evaporate  1  cubic  foot  of  water. 


Strength  of  Boilers. 

T  x  f 

Bursting  strength  of  shell  :    P  = 

Where— 

P  =  bursting  pressure  in  Ibs.  per  square  inch. 

T  —  thickness  of  plate  in  sixteenths  of  an  inch. 

D=  diameter  of  shell  in  feet. 

C  =  for  wrought  iron  (single  riveting)  .  .  1,097 
.,  „  „  (double  ,  ').  .  1,372 

.,  steel  (  „  „  )  .  .  2,156 

^  ,,  (single  „  ).  .  1,722 

87'4  x  T2 
Collapsing  pressure  of  tubes  :   P  =  — — 

Where— 

P  =  collapsing  pressure  in  Ibs.  per  square  inch. 
T  =  thickness  of  tube  in  thirty-seconds  of  an  inch. 
L  =  length  in  feet. 
D  =  diameter  in  inches. 

Thickness  of  fire  bars,  i  to  f  inch  ;  space,  f  to  £  inch  ;  inclination 
of  bars,  1  in  10  to  1  in  12  ;  height  of  dead  plate  above  floor,  2  feet 
8  inches  ;  minimum  height  of  water  over  flue,  4  inches  ;  average 
height  of  water  over  flue,  9  inches  ;  inclination  of  boiler  towards 
blow-off  cock  in  setting,  A  inch  in  10  feet. 

Cornish  or  Lancashire  boilers  firegrate  area  X  4  =  H.  P. 

Cornish  or  Lancashire  boilers  usually  require  7  square  feet  heating 
surface  per  horse-power.  Heating  surface  should  be  20  times,  and 
never  less  than  10  times,  firegrate  area  ;  or, 


TT  p Diameter  of  cylinder  in  inches  9  x  V  stroke  in  inches 

3.25 


174  GAS  ENGINEER'S  POCKET-BOOK. 

If  more  than  one  cylinder  Da  =  sum  of  the  squares  of  the  diameters 
of  the  pistons. 
Approximate   rule  for   the    nominal   horse-power  of  cylindrical 

L1  X  D1 

two-nued  boiler  is  -  -  =  H.P. 


Safe  Pressure  on  a  Circular  Boiler. 

2tfv 
~~dT 

P  =  safe  pressure  in  pounds  per  square  inch. 
t  =  thickness  of  shell  in  inches. 

/=  tensile  strength  of  plate  in  pounds  per  square  inch. 
/•  I  =  for  ordinary  iron  boiler  plates,  20  tons. 
*  \  =  for  steel  boiler  plates,  28  tons. 
d  =  diameter  of  boiler  in  inches. 
k  =  in  ordinary  cases  6.        k  =  factor  of  safety. 

!  =  for  single  riveting  40  per  cent. 
=  for  double  riveting  60  per  cent. 
=  for  butt  joints  70  per  cent. 
v  =  efficiency  of  the  riveted  joints. 

Pressure  in  Boilers. 

Circumferential  bursting  pressure  is  numerically  equal  to  the  area 
of  the  end  X  the  pressure  per  square  inch. 

Bursting  pressure  longitudinally  equals  pressure  per  square  inch  X 
diameter  in  inches. 

In  a  cylindrical  shell  the  intensity  of  longitudinal  stress  is  only 
half  as  great  as  the  intensity  of  circumferential  stress. 

Safe  Working  Pressure  on  Boiler  Furnace  Tubes. 


~  (L  +  1)  X  D 

8,000  t 
P  should  not  exceed  —  jj— 

P  =  safe  pressure. 

t  =  thickness  of  plate  in  inches. 

L  =  length  of  tube  in  feet. 

C  =  60,000  if  seams  are  lap-jointed,  single  riveted,  and  punched. 

D  =  diameter  of  tube  in  inches. 

Safe  Working  Pressure  on  Iron  Tubes      CM.  Longridge.) 
Ibs.  per  square  inch  working  pressure  =  H~TF- 

t  =  thickness  in  32nds  inch. 
d  =  diameter  in  inches. 
L  =  length  of  tubes  in  feet. 


BOILERS.  175 

Duty  Obtained  from  Coke-Fired  Water-Tube  Boilers. 

Evaporative  duty  per  pound  coke  =  10-05  Ibs.  water. 

Mean  steam  pressure  per  square  inch=  143-3  Ibs. 

Mean  temperature  of  feed- water  =  185°  F. 

Mean  temperature  of  waste  gases  =  527°  F. 

Air  supplied  per  pound  of  combustible  =  22-39  Ibs. 

Coke  used  =  ashes  and  cinders  =  8-26  per  cent. 

Coke    used  =  calorific   value    per  pound  =  13,186*98    British 

thermal  units. 
Heat  communicated  to  water  =  79*21  per  cent. 

A  Flaw  in  the  Thickness  of  a  Boiler  Plate  or  the  least  separation 
between  two  plates  when  bolted  together  is  almost  sure,  if  exposed 
to  too  strong  a  heat,  to  cause  injury  to  the  boiler. 

Rate  of  Transmission  of  Corrected  Heat  through  metal  plates  equals 
2  to  5  British  thermal  units  per  hour  per  square  foot  of  surface  per 
1°  F.  of  difference  of  temperature.  (D.  K.  Clark.) 

A  Boiler  is  said  to  have  been  Overheated  when  the  boiler  plate 
has  become  red  hot  at  any  given  spot,  and  the  phenomenon  is  recog- 
nised by  the  bluish  shade  the  iron  assumes  when  cold,  due  to  the 
formation  of  a  layer  of  oxide.  Overheating  alters  the  quality  of  the 
metal  and  disintegrates  the  joints,  and,  unless  at  once  detected  and 
remedied,  it  ultimately  results  in  an  explosion. 

The  reason  generally  assigned  is  an  insufficient  supply  of  feed- 
water. 

If  the  boiler  plates  overlap,  the  transmission  of  heat  is  more  or  less 
impeded.  Even  a  well  made  joint  ought  not  to  be  exposed  to  too 
fierce  a  fire.  (J.  Hirsch.) 

Proportion  of  Riveted  Joints  of  Maximum  Strength. 
(D.  K.  Clark.) 

Thickness  of  plate  =  1 

Diameter  of  rivets  =  2 

Pitch  of  rivets  (single)  =  5J 

Pitch  of  rivets  (double)  =  8 

Diagonal  pitch  of  rivets  (double)  =  6 

Spacing  (double)  =  4£ 

Lap  (single)  =  6 

Lap  (double)  =  10J 

Single  riveted  joint  =  about  *56  of  the  plate. 

Double      „          .,    =     „     -7        „        „ 

Single  butt  straps  should  be  1$  times  as  thick  as  the  plates. 

Double  butt  straps  should  be  each  f  times  as  thick  as  the  plates. 

Size  of  Rivets  for  Various  Thicknesses  of  Boiler  Plates. 

f  and  ^  inch  plates — f  inch  rivets. 

1  9  13 

2  55       TB        >'  55  16        5)  )5 

ti        V         §  „  5-        ~l 

I        „         1  ,        -M 


176        GAS  ENGINEER'S  POCKET  BOOK. 

Safety  Valves. — According  to  the  Board  of  Trade  rules  the  area 
of  a  safety  valve  for  a  boiler  working  at  50  Ibs.  pressure  is  576  square 
inches  per  square  foot  of  firegrate. 

Another  rule  is  A  =  g^-p  +  a 

Where  a  =  area  of  guides  of  valve,  P  =  absolute  pressure  of  steam 
in  pounds  per  square  inch,  W  =  weight  of  steam  evaporated  per  hour 
in  pounds,  A  =  area  of  valve  in  square  inches. 

Theoretically,  only  7'5  per  cent,  of  the  calories  developed  in  the 
furnace  of  a  boiler  appears  as  work  in  the  engine.  (Hirsch.) 

At  a  rough  computation,  petroleum  burnt  as  fuel  under  a  boiler 
should  need  only  three-fifths  the  storage  room  of  coal  for  the  same 
duty  ;  and  whatever  further  advantage  calcium  carbide  has  in  point 
of  compactness  is  mainly  due  to  the  superior  efficiency  of  the  gas 
engine  to  the  steam  engine. 

A  non-condensing  engine  requires  3  Ibs.  of  coal  per  I.H.P.  per  hour. 

A  condensing  „  „        2  Ibs.  „       „  „  „ 

Set  Boilers  in  mortar  made  of  soft  sand  2  parts,  lime  1^  parts, 
sharp  sand  1£  parts,  except  where  the  bricks  or  lumps  touch  the 
boilers,  when  fireclay  should  be  used. 

Mr.  C.  Gandon  found  that  the  foundations  of  a  boiler  made  of 
furnace  clinker  and  cement,  with  three  layers  of  firebrick  bedded  in 
fireclay,  had  caught  fire  from  the  flues,  and  the  whole  mass  of  the 
foundations  was  on  fire. 

Large  flues  around  boilers  cause  a  slow  passage  of  gases. 

Area  of  chimney  =  1<5  (area  o£  firegrate  in  Squar°  ***? 

^/height  of  chimney  in  feet 

Superheaters  in  boiler  flues  for  superheating  steam  give  a  gain  of 
10  per  cent,  to  25  per  cent.,  according  to  type  of  engine  used. 

In  Lancashire  boilers  all  furnace  flue  seams  should  be  below  the 
grate  bars,  longitudinal  joints  of  shell  butted  and  fitted  with  covers 
inside  and  out,  double  riveted  zigzag,  with  outer  rows  twice  the  pitch 
of  the  inner  ones. 

For  ordinary  draught,  when,  say,  from  20  to  25  Ibs.  of  coal  is 
burnt  per  hour  per  square  foot  of  firegrate,  the  average  proportions 
to  allow  per  I.H.P.  are — 

£  square  foot  of  firegrate. 
2|  „          of  heating  surface. 

1J  cubic  feet  of  water  space. 
I          „          of  steam  space. 

English  coal  will  evaporate  8  to  9'88  Ibs.  water  at  and  from  212°  F. 
Scotch  coal  will  evaporate  6'69  Ibs.  water  at  and  from  212°  F. 
Fuel   consumption    per    I.H.P.  may  be  anything  from    1-3   Ibs., 
according  to  class  of  boiler,  engine,  and  method  of  working. 

Boiler  Chimneys. 

Allow  3£  square  feei  chimney  area  for  each  full-sized  Lancashire 
boiler,  or  4  square  feet  for  a  single  boiler  ;  height  of  chimney  same  as 
others  in  neighbourhood,  preferably  not  less  than  90  feet  high. 


CHIMNEYS. 
Dimensions  of  Chimneys.     (R.  Wilson.) 


177 


Area  of  Top 

Height 
of 
Chim- 
ney. 
Feet. 

Lbs.  of  Coal 
per  Hour 
per  1  Foot 
Area  at  Top 
of  Chimney. 

Height  in 
Inches  of 
Water 
Balanced 
by  Draught 
Pressure. 

H.P.  of  each 
Square  Foot 
of  Chimney 
at  7  Ibs.  Coal 
per  H.P. 

Area  of  Top 
of  Chimney 
in  Feet  per 
H.P.  for  1 
or  2  Boilers. 

of  Chimney 
in  Feet  per 
H.P.  where 
several 
Boilers 
work 

Area 
of  Flue 
in  Feet 
per 
H.P. 

together. 

30 

78-24 

•218 

7-3 

•146 

•091 

•182 

40 

90-35 

•296 

8-4 

•126 

•077 

•155 

50 

101-01 

•364 

9-4 

•113 

•070 

•140 

60 

110-65 

•437 

10-3 

•103 

•C64 

•129 

70 

119-52 

•5 

11-2 

•095 

•059    ' 

•119 

80 

127-77 

•58 

11-9 

•089 

•055 

•111 

90 

135-52 

•656 

12-6 

••084 

•052 

•105 

100 

142-85 

•729 

13-3 

•08 

•05 

•100 

125 

159-71 

•911 

14-9 

•071 

•044 

•089 

150 

174-96 

1-09 

16-3 

•065 

•04 

•082 

175 

188-98 

1-26 

17-6 

•060 

•038 

•075 

200 

202-03 

1-45 

18-8 

•056 

•035 

•070 

225 

214-28 

1-64 

20-0 

•053 

•033 

•066 

250 

225-87 

1-82    ,i 

21-0 

•05 

•031 

•063 

275 

236-90  , 

1-99 

22-0 

•048 

•03 

•06 

300 

247-43 

2-18 

23-0 

•046 

•028 

•057 

Armstrong  proposes  from  20  to  40  per  cent,  above  these  sixes,  and 
to  allow  for  additions  to  boilers  it  would  be  advisable  to  exceed  above 
sizes  to  that  extent. 

Proportion  of  Chimneys. 

Diameter  of  base,  ^th  height. 

Brickwork  9  inches  thick  for  the  top  25  feet. 

Brickwork  14  inches  thick  from  25  to  50  feet  from  the  top. 

Brickwork  18  inches  thick  from  50  to  75  feet  from  the  top. 

Brickwork  23  inches  thick  from  75  to  100  feet  from  the  top. 

Increasing  4^  inches  thick  for  every  extra  25  feet. 

Knle  for  Area  of  Chimney  if  21  Ibs.  of  Coal  are  Consumed  per 
Square  Foot  Grate  Area  per  Hour. 

Area  of  firegrate,  in  square  feet,  X  H  +  *J  height  in  feet  =  area  in 
square  feet. 

Or,  one-eighth  to  one-tenth  grate  area  =  area  of  chimney. 
.Draught  of  Chimneys. 

1  cubic  foot  air  at  30"  Bar.  and  60°  F.  =  0-0763  Ibs.  and  varies  as 
absolute  temperature.    Then  if  chimney  gases  are  at  550°  F- 
0-0763  X  (460  +  60) 


4b'0  +  550 

0-0763  -  0-0393  =  0-037  Ibs.  per  foot  height  per  square  foot  area  of 
chimney  or  height  of  chimney  for  1"  draught  in  feet 

5-21  (=  Ibs.  per  square  foot  of  1"  pressure)  _  ^  ,, 

~&WT- 

Or,  approximately  —  draught  in  inches  of  water  =  0-0075  x  height 
chimney.     Then  0-0075  x  111  -  1  -0575  inches  draught. 


of  chimne 
G.E. 


178 


GAS    ENGINEERS    POCKET-BOOK. 


To  Find  Size  of  Chimney  Required. 

For  a  low-pressure  engine,  when  above  10  H.P.,  the  area  of  the 
chimney  in  square  inches  should  be  280  times  the  horse-power  of 
the  engine  divided  by  the  square  root  of  the  height  of  the  chimney 
in  feet.  (Joshua  Milne,  of  Olclham.) 

Or,  multiply  the  square  root  of  the  chimney  height  in  feet  by  the 
square  of  its  narrowest  internal  diameter  in  feet  ;  half  the  product 
will  be  the  horse-power  the  chimney  is  equal  to. 

90  v  TT  P 
Or,  for  circular  chimney,  the  diameter  = 

^/height  in  feet 

Or,  firegrate  should  /have  1  foot  area  per  horse-power,  one-fifth 
area  of  firegrate,  gradually  diminishing  to  a  chimney  which  shall' 
have  one-tenth  area  of  firegrate,  is  excellent  proportion.  (Cresy.) 

Or>     2  x  112  x  cubic  feet  evaporated  per  hour  __  Square  inches 
\/height  in  feet  area> 

Coal  Consumable  by  Chimneys  of  Different  Sizes.     (D.  K.  Clark.) 


Chimney. 

Coal. 
Hour. 

Grate 
Area. 

Chimney. 

Coal 
per 
Hour. 

Grate 
M.rea. 

Height. 

Diameter. 

Height. 

Diameter. 

Feet. 

Ft.  Ins. 

Lbs. 

Sq.  Ft, 

Feet. 

Ft.  Ins. 

Lbs. 

Sq.  Ft. 

40 

1   4 

142 

9-5 

110 

3  8 

1777 

118-4 

50 

1   8 

248 

16-5 

120 

4  0 

2208 

147-2 

60 

2  0 

390 

26-0 

135 

4  6 

2964 

197-6 

70 

2  4 

574 

38-3 

150 

5  0 

3858 

257-2 

80 

2  8 

801 

53-4 

165 

5  6 

4896 

326-4 

90 

3  0 

1076 

71-7 

180 

6  0 

6086 

405-7 

100 

3  4 

1394 

93-0 

200 

6  8 

7920 

526-6 

Diameter  = 


height  ;  coals  consumed,  15  Ibs.  per  square  foot 
per  hour. 


Metropolitan  Board  of  Works  Regulations  as  to  Factory  Chimneys. 

Base  of  shaft  to  be  solid  up  to  top  of  footings  ;  projection  of 
footings  equal  all  round,  and  to  thickness  of  wall  at  base. 

Width  of  shaft  at  base,  just  above  footings  :  — 

If  square  on  plan,  at  least  T^th  total  height. 

If  octagonal  on  plan,  at  least  JLth  total  height. 

If  circular  on  plan,  at  least  J5th  total  height. 

Batter  at  least  2J  inches  in  every  10  feet,  or  1  in  48. 

Brickwork  at  least  8J  inches  thick  at  top  and  for  20  feet  down,  and 
increased  4£  inches  for  every  20  feet  additional  height  ;  firebrick 
lining  to  be  separate,  and  not  included  in  above  thicknesses. 

Cornice  not  to  project  more  than  the  thickness  of  walls. 


CHIMNEYS. 


179 


Velocity  of  gases  up  the  chimney  being  proportional  to  the  square 
root  of  the  height,  increased  duty  would  be  better  obtained  by  larger 
diameter  than  by  greater  height. 

The  heavier  the  materials  of  which  a  shaft  is  built  the  greater 
would  be  its  stability,  the  foundations  being  good. 

Batter  of  chimneys  may  equal  1  in  36. 

Theoretical  draught  power  of  chimneys  with  external  air  =  60°  F.; 
internal  heated  air  =  580°  F.  (coefficient  in  practice  *3). 


Height  of 
Chimnev 
in  Feet! 

Draught  in 
Inches 
of  Water. 

Theoretical  Velocity  in  Feet  per  Second. 

Cold  Air  Entering. 

Hot  Air  at  Outlet. 

50 

•367 

40-0 

80-8 

60 

•440 

43-8 

87-6 

70 

•514 

47-3 

94-6 

80 

•587 

50-6 

101-2 

90 

•660 

53-7 

107-4 

100 

•734 

56-6 

113-1 

120 

•880 

62-0 

123-9 

150 

1-101 

69-3 

138-6 

175 

1-285 

74-8 

149-6 

200 

1-468 

80-0 

160-0 

225 

1-652 

84-8 

169-7 

250 

1-836 

89-4 

178-9 

275 

2-020 

93-8 

187-6 

300 

2-203 

98-0 

196-0 

(Bancroft.) 

The  wind  pressure  on  chimney  shafts  may  be  taken  as  acting  upon 
the  centre  of  gravity  and  in  a  horizontal  direction,  and  the  over- 
turning moment  equals  the  height  of  the  centre  of  gravity  (/«-)  above 
the  point  at  which  it  is  desired  to  obtain  the  strength,  as  at  a  J,  x 
wind  pressure  on  chimney  ;  the  least  moment  of  stability  must 
therefore  exceed  this  {for  figure  see  next  page). 

The  pressure  of  the  wind  will  tend  to  move  the  centre  of  pressure 
on  a  b,  towards  the  leeward  side. 

To  obtain  the  moment  of  stability  of  any  shaft  take  weight  of  shaft 
above  a  b  x  ^  a  b. 

Kankine  says  a  factor  of  safety  of  2  is  necessary  for  round  shafts 
and  of  |  for  square  shafts. 

It  has  been  said  that  the  limiting  position  of  the  centre  of  pressure 
is  permissible  to  be  at  one  sixth  of  the  diameter  from  the  leeward 
side  for  square  shafts,  and  one  quarter  of  the  diameter  from  the  side 
for  round  shafts,  only  when  the  brickwork  becomes  infinitely  thin. 

Firebrick  lining  to  boiler  chimneys  need  not  be  more  than  one  half, 
or  at  most  two  thirds,  the  total  height. 

If  wind  pressure  on   square   shaft        =  1 
then  .,  „  „     hexagonal  shaft  =     '75 

„      „  „  „     octagonal  shaft    =     '7 

•3     „  „  „     circular  shaft       =    -5       (Bancroft.) 

N2 


180 


GAS    ENGINEERS    POCKET-BOOK. 


LIGHTNING   CONDUCTORS.  181 

Chimney  shafts  should  not  be  joined  to  any  other  work  of  buildings, 
in  case  of  settlement  or  expansion. 

Grouting  is  not  advisable,  as  wet  mortar  possesses  little  adhesive 
power  ;  and  the  building  should  not  proceed  at  a  greater  rate  than 
2  feet  to  3  feet  per  diem.  Only  one  course  of  headers  should  be  used 
in  large  chimneys  to  three  or  four  of  stretchers.  Capping  stones 
should  be  light  and  joined  with  copper  cramps  at  joints,  as  iron 
rusts  and  expands,  when  the  stone  may  split  and  fall. 

Stock  bricks  will  bear  a  heat  of  600°  F.  without  damage. 

Higher  heat  at  exit  of  chimney  than  580°  F.  or  305°  C.  is  wasteful. 

Less  exhaust  than  £  inch  water  bad. 

580°  F.  gives  a  head  of  external  air  equal  to  half  the  height  of 
chimney. 

By  the  usual  rule,  the  external  diameter  at  base  of  chimney  should 
be  about  ith  of  the  height,  and  the  batter  fg  inch  to  £  inch  per  foot 
on  each  side. 

It  is  frequently  stated  in  treatises  on  chimney  designs  that  the 
diameter  at  the  base  should  be  ^th  to  ^th  the  height,  but,  having 
regard  to  the  paramount  importance  of  width  of  base,  the  width 
obtained  by  this  rule  is  insufficient. 

For  further  remarks  on  chimney  shafts,  see  Bancroft  on  "  Design  of 
Tall  Chimneys." 

Lightning  Conductors. 

Copper  is  the  best ;  but,  when  corrosion  is  not  anticipated,  iron  of 
larger  dimensions  may  be  used  (conductivity  of  iron  equals  |th  that  of 
copper). 

General  dimensions  of  copper  conductors  : — Rods  £  inch  diameter, 
tubes  f  inch  diameter,  |  inch  thick  ;  or  bands  1£  inch  wide  f  inch 
thick. 

General  dimensions  of  iron  conductors : — Kods  1  inch  diameter, 
bands  2  inches  wide  x  f  inch  thick. 

Radius  of  protection  of  lightning  conductors  equals  height  from 
ground. 

Sir  William  Thomson's  (Lord  Kelvin's)  note  advocates  the  use  of 
the  flat  (tape  or  sheet)  form  of  conductor  in  preference  to  the  tubular 
or  solid;  and,  if  copper  be  used,  its  weight  should  be  about  6  oz.  to  the 
foot ;  if  iron,  about  35  oz.  It  quotes  Lodge's  recommendation  that 
the  conductor  should  be  connected  with  the  water  or  gas  mains  if  in 
any  part  of  its  course  it  goes  near  them,  but  concedes  that  independent 
grounds  are  preferable.  It  gives  the  usual  advice  as  to  electrical 
connection  with  masses  of  metal  built  into  a  building,  and  warns 
against  the  neighbourhood  of  small-bore  fusible  gas  pipes  and  indoor 
gas  pipes  in  general.  It  prefers  clusters  of  points,  or  groups  of  two 
or  three,  along  the  ridge  rod,  to  other  arrangements,  and  regards 
chain  or  link  conductors  as  of  little  use.  That  the  area  protected  is 
one  of  a  radius  equal  to  twice  the  height  of  the  rod  from  the  ground, 
or  even,  as  some  conductor  manufacturers  aver,  a  radius  equal  to  the 
height,  is  denied.  No  such  thing  as  a  definite  area  exists.  That 
lightning  follows  the  path  of  least  resistance  is  also  controverted,  for, 
in  exceptional  instances,  when  the  flash  is  of  a  certain  kind  any  part 
>f  a  building  is  liable  to  be  struck,  whether  there  is  a  conductor  or  not 


182  GAS  ENGINEER'S  POCKET-BOOK. 

Lightning  may  also,  contrary  to  what  is  generally  held,  strike  twice 
in  the  same  place.  Doorways  of  barns,  chimneys,  and  fireplaces  are 
dangerous  places,  but  the  smaller  articles  of  steel,  such  as  knives,  &c., 
have  no  influence  on  the  path  of  discharge.  The  best  made-ground 
for  the  earth-plates  is,  for  some  flashes,  but  a  very  poor  one  ;  damp 
earth  or  running  water  are  still  the  best  terminations  known. 

Steam  Pipes. 

Thickness  of  steam  pipe  in  IGths  of  an  inch  equals  diameter 
(inches)  -f-  4  up  to  100  Ibs.  pressure. 

D  P 

Above  this  T  =  —  —  +  £          T  =  thickness  in  inches. 

TjOOO 

Steam  should  have  a  velocity  of  about  6,000  feet  per  minute  through 
steam  pipes  ;  same  for  ports  of  engine. 
To  find  diameter  of  steam  pipes  for  any  engine  : 

*  /  Sq.  of  cylinder  diar.  in  inches  x  piston  speed  in  feet  per  mm. 

6,000 

=  The  required  diameter  of  steam  pipe. 

100  feet  of  4-inch  pipe  would  waste  as  much  heat  per  annum  as  the 
consumption  of  50  tons  of  coal  would  supply.  With  an  efficient 
lagging  it  is  to  be  supposed  that  most,  if  not  all,  of  this  would  be 
saved.  (Mr.  G-eipel.) 

Allow  1  inch  expansion  in  50  feet  in  steam  pipes. 
A  4  H.P.  engine  requires  only  2-inch  diameter  steam  connections. 

Exhaust  Pipe. 

To  prevent  undue  back  pressure  velocity  of  steam  should  not  be 
greater  than  4,000  feet  per  minute. 
To  find  diameter  of  exhaust  pipe : 

Square  of  cylinder  diameter  x  piston  speed  in  feet  per  minute 

4,000. 

The  square  root  of  the  quotient  gives  diameter  of  pipe  in  inches; 
same  for  ports  of  engine. 

Condensation. 

The  water  required  for  condensation  is  about  20  times  that  required 
for  the  feed  -  approximate  area  of  condensing  surface  =  heatinjr 
surface  x  0*7. 

Comparative  Efficiency  of  Non-conducting  Materials.     (Emery.) 


Wood  felt  1-000 

Mineral  wool,  No.  2  -832 

„          „     with  tax  -715 

Sawdust  -680 

Mineral  wool,  No.  1  M>7<> 

Charcoal  '(J',V2 

Pine  wood,  across  fibre  '553 


Loam,  dry  and  open  '550 

Slaked  lime  '480 

Retort  carbon  -470 

Asbestos  -363 

Coal  ashes  '345 

Coke  in  lump  '277 

Air  space  undivided  '136 


DISTANCE    BETWEEN    BEARINGS    OF    SHAFTS. 


182 


Diagram  showing  Span  between  Bearings  of  Shafts. 

Feet  centres  of  Journals. 


C  =  6  C  =  4-5 

From  the  rule  S  =  C  v 

S  =  span  between  bearings  in  ftet. 


%  where  D  =  diameter  of  shaft. 

f  5  to  6  for  shaft  only,  without  pulleys. 
C  =  ]  4-5  to  5  lor  shaft,  with  ordinary  number 

'     of  pulleys  and  wheels. 


184 


GAS  ENGINEER'S  POCKET-BOOK. 


Non-Conductors  for  Steam  Pipes.     (Prof.  J.  M.  Ordway.) 


Lbs.  Wate 

Lbs.  Water 

Heated 

Heated 

Substance,  1  Inch  Thick. 

10°  F. 

Substance,  1  Inch  Thick. 

10*  F. 

Heat  Applied,  310°  F. 

per  Houi 

Heat  Applied,  310°  F. 

per  Hour 

through 

through 

1  Sq.  Ft. 

1  Sq.  Ft. 

Loose  wool  . 

81 

Air  alone         .        .     . 

4S-0 

Live-geese  feathers     . 

9-6 

Sand    ....       62-1 

Carded  cotton 

10-4 

Best  slag  wool        .     . 

13-0 

Hair  felt         .        .    . 

10-3 

Paper  .... 

14-0 

Loose  lampblack 
Compressed  ditto    .     . 

9-8 
10-6 

Blotting  paper,  wound 
tight 

21-0 

Cork  charcoal 
White  pine  charcoal   . 

11-9 
13-9 

Asbestos  paper,  wound 
tight 

21-7 

Anthracite  coal  powder 

35-7 

Cork  strips,  bound  on 

14-6 

Loose    calcined    mag- 

Straw    rope,     wound 

nesia 

12-4 

spirally        .        .     . 

18-0 

Compressed     calcined 

Loose  rice  chaff  . 

18-7 

magnesia  . 

42-6 

Paste    of    fossil  meal 

Light     carbonate     of 

with  hair 

16-7 

magnesia  . 

13-7 

Paste    of   fossil  meal 

Compressed  carbonate 

with  asbestos  . 

22-0 

of  magnesia     . 

15-4 

Loose  bituminous  coal 

Loose  fossil  meal    .     . 

14-5 

ashes 

21-0 

Crowded  fossil  meal    . 

15-7 

Loose  anthracite  coal 

Ground    chalk   (Paris 

ashes 

27-0 

white) 

20-6 

Paste    of     clay     and 

Dry  plaster  of  Paris    . 

30-9 

vegetable  fibre 

30-9 

Fine  asbestos 

49-0 

Notes  on  Pumps. 

A  man  exercises  more  power  with  an  ordinary  pump  handle  than 
with  a  crank  and  handle.  The  power  exerted  by  an  ordinary  man  in 
working  a  pump  handle  continuously  must  not  be  estimated  above 
25  Ibs.  The  suction  and  delivery  pipes  of  pumps  should  not  be  less 
than  one  half  the  diameter  of  the  barrels  ;  and  if  the  length  be  great, 
they  should  be  larger  ;  also  with  large  pumps  or  pumps  working  fast 
it  is  well  to  have  a  greater  proportion  of  pipe  area  (in  some  cases  the 
pipe  is  made  as  large  as  the  barrel).  The  suction  pipe  should  also  be 
larger  than  the  delivery  pipe,  as  in  the  suction  pipe  there  is  only  the 
atmospheric  pressure  to  overcome  the  friction,  whereas  in  the  delivery 
pipe  there  is  the  whole  power  of  the  pump.  The  following  is  a  safe 
rule  for  the  sizes  of  suction  pipes.  An  advantage  is  gained  by  using 
a  large  suction  pipe,  even  if  the  inlet  of  the  pump  be  smaller  than 
the  pipe. 

Inch.    Inch.    Inch.    Inch.   Inch.    Inch.   Inch. 
Size  of  pump        2        2-J-        3        34-      4        5         6 
Siee  of  suction      1£       H        2        2        2£      3         4 


PUMPS.  185 

These  sizes  hold  good  for  double  pumps,  as  each  barrel  draws 
alternately,  and  therefore  the  pipe  need  not  be  increased  in  size.  In 
laying  a  long  length  of  suction  pipe  make  sure  that  it  falls  along  its 
whole  length  from  the  pump  towards  the  well.  If  there  is  any  point 
higher  than  the  pump  end  of  the  pipe  it  will  form  a  pocket  or  trap 
from  which  it  will  be  very  difficult  to  draw  the  air.  It  is  always 
desirable  to  have  a  foot  valve  in  the  suction  pipe  to  retain  the  water 
when  the  pump  is  standing.  To  avoid  concussion  and  equalise  the 
working  of  the  pump  it  is  well  to  place  a  vacuum  vessel  on  the  pipe 
just  before  it  enters  the  pump. 

Formula  for  calculating  the  power  required  to  raise  water  :— 
Gallons  per  minute  x  height  in  feet 

=  horse-power 

3,300 
Add  for  friction  according  to  the  machinery  used  and  length  of  piping. 

Capacities  of  Pumps. 


Dia- 
meter. 
Inches. 

Area  in 
Inches. 

Displacement 
in  Gallons  per 
Foot  of  Travel. 

Dia- 
meter. 
Inches. 

Area 
in  Inches. 

Displacement 
in  Gallons  per 
Foot  of  Travel. 

i 

•0129 

•0005 

4* 

14-18 

•6125 

| 

•0490 

•0021 

4i 

15-90 

•6868 

•1104 

•0047 

4f 

17-72 

•7655 

I 

•1963 

•0084 

5 

19-63 

•8480 

•3068 

•0132 

H 

21-54 

•9348 

! 

•4417 

•0190 

5£ 

23-75 

1-026 

i 

•6018 

•0259 

5f 

25-96 

1-121 

i 

•7854 

•0339 

6 

28-27 

1-221 

ii 

•9940 

•0429 

6J 

30-67 

1-325 

H 

1-227 

•0530 

6i 

33-18 

1-433 

if 

1-484 

•0641 

8| 

35-78 

1-545 

H 

1-767 

•0763 

7 

38-48 

1-662 

if 

2-073 

•0895 

74 

41-28 

1-783 

if 

2-405 

•1038 

7f 

44-17 

1-908 

if 

2-761 

•1192 

7f 

47-17 

2-037 

2 

3-141 

•1356 

8 

50-26 

2-171 

*i 

3-546 

•1531 

8| 

53-45 

2-309 

2i 

3-970 

•1717 

8} 

56-74 

2-451 

21 

4-430 

•1913 

8| 

60-13 

2-597 

2J 

4-908 

•2120 

9 

63-61 

2-747 

2* 

5-411 

•2337 

9* 

67-20 

2-903 

2| 

5-939 

•2565 

9} 

70-88 

3-062     ' 

2£ 

6-491 

•2804 

9f 

74-66 

3-225 

3 

7-068 

•3053 

10 

78-54 

3-393 

S| 

7-669 

•3313 

10* 

82-51 

3-564 

3* 

8-295 

•3583 

10* 

86-59 

3-740 

N 

8-946 

•3864 

lOf 

90-76 

3-920 

3* 

9-621 

•4156 

11 

95-03 

4-105 

N 

10-32 

•4458 

11* 

99-40 

4-294 

3| 

11-04 

•4769 

IH 

103-8 

4-484 

3£ 

11-79 

•5193 

nf 

108-4 

4-682 

4 

12-56 

•5426 

12 

113-0 

4-881 

186 


GAS  ENGINEER'S  POCKET-BOOK. 


The  following  rule  shows  how  to  determine  the  dimensions  of  the 
feed  pump  : — 

Let  D  =  diameter  of  steam  cylinder  in  inches. 

L  =  length  of  stroke  up  to  point  of  cut-off  in  inches. 
s  =  stroke  of  pump. 
d  =  diameter  of  pump. 

v  =  volume  of  steam  obtained  from  1  cubic  foot  of  water  at 
the  given  pressure. 

Then     d  =  21 

Force  pumps  should  be  twice  the  diameter  of  the  pipes  in  connec- 
tion. 

Horse-power  required  to  raise  water  equals  quantity  of  water  to 
be  raised  in  gallons  per  minute  X  10  X  height  to  be  lifted  in  feet 
divided  by  33,000.  Add  £  to  §  for  losses  by  slip  of  valves  and  friction. 

Table  of  Pedestal  Proportions.     (Unwin.) 


Dia- 
meter of 
Journal. 
Inches. 

Length 
of 
Bearing. 
Inches. 

Height 
to 
Centre. 

Diameter 
of  Bolts. 

Size  of 
Bolt 
Holes. 

Length 
of  Base. 

Centres 
of  Cap 
Bolts. 

Centres 
of  Base 
Bolts. 

Thick- 
ness of 
Step  at 
Bottom. 

li 

2* 

4 

\ 

|xi 

81 

H 

*i 

ito& 

2 

3 

2f 

fxii 

11 

4f 

9 

/ii    I 

H 

8* 

*k 

| 

ixU 

13i 

H 

10J 

5             7 
TO           16 

3 

4 

81 

i 

i  xif 

15i 

*l 

|2| 

1            i 

3i 

!* 

4 

1 

Uxif 

m 

7 

H! 

1            J 

4 

5 

H 

l| 

HX2 

20 

7* 

WJ 

7^             i» 
10            16 

5 

6 

6 

If 

lfX2i 

24 

9i 

19| 

i      t 

6 

7 

7 

1| 

1JX2J 

28i 

llf 

23f 

JL         13 
10           16 

7 

8 

8* 

Two  li 

lfX2i 

— 

12i 

— 

1      i 

8 

9 

9* 

.»    H 

1IX2J 

— 

14 

— 

tt      1 

9 

10 

10i 

»    if 

l*X2i 

— 

15} 

— 

1      1 

10 

11 

11* 

„    if 

2   X2f 

— 

m 

— 

1      li 

12 

13 

18J 

»     2* 

2|X3| 

— 

21 

— 

1      li 

From  seven  inches  upwards  the  pedestals  have  two  bolts  on  each 
side,  both  in  cap  and  base  plate. 

Length  of  Engine  Journals. 

The  higher  the  speed  the  greater  the  length  of  journal  required. 
At  150  revolutions  per  minute  one  diameter  is  sufficient  ;  at  1,500 
revolutions  per  minute  6  or  8  diameters  are  better. 

Coefficient  of  Friction  with  Dry  Surfaces, 

Metal  on  metal  0'15  to  0-20 
Wood  „  „  0-25  to  0-30 
Millboard  .,  0.20 


GEARING.  187 

When  polished  steel  moves  on  steel  or  pewter  properly  oiled  the 
friction  is  about  £  of  its  weight ;  on  copper  or  lead  |,  on  brass  £. 

Metals  working  on  same  metals  give  more  friction  than  when  on 

different  metals.  

3    /p  x  i 

Diameter  of  engine  crank  shafts  =       — — — 

& 

P  =  pressure  of  steam  on  piston. 
Z  =  length  of  crank  in  feet. 
K=80  for  iron,  120  for  steel. 

Safe  Speed  for  Flywheels. 

Maximum  safe  circumferential  velocity  of  cast  iron  flywheels  is 
80  feet  per  second.  Speed  should  not  exceed  in  revolutions  per 
minute 

1530 

mean  diameter  in  feet. 

Width  of  Rim  of  Pulley  for  Belts  of  Various  Widths.    (Unwin.) 

Ins.        Ins.  Ins.       Ins.       Ins.        Ins.      Ins.  Ins. 

Width  of  belt      2  3  4          5         6         8          10  12 

Widthofpulley  2|         3J        5          6         7±        9*        llf         14 

Thickness  of  edge  of  rim  equals  0'7  thickness  of  belt  -j-  '005  times  the 
diameter  of  pulley. 

Radius  of  rim  face  equals  3  times  to  5  times  the  breadth  of  rim. 

Diameter  of  pulleys  should  not  be  less  than  6  to  8  times  the  dia- 
meter of  a  wrought  iron  shaft  suitable  for  transmitting  the  power 
transferred  to  the  belt,  and  the  diameter  of  the  smaller  of  two  pulleys 
should  not  be  less  than  about  18  times  the  belt  thickness. 

Breaking  weight  of  machine  belting,  leather,  per  square  inch 
equals  1'9  tons. 

Leather  hose  and  driving  belts  for  machinery  treated  with  castor 
uil  have  been  found  to  last  longer,  and  when  impregnated  will  not 
slip.  A  3-inch  belt  treated  with  castor  oil  equals  a  4i-inch  belt 
without  oil,  and  will  last  more  than  twice  as  long. 

Proportion  of  Teeth  of  Wheels. 


Depth  =  pitch  x  '75 

Working  depth  =     „      x  '70 
Clearance          =     .,      x  '05 


Thickness  =  pitch  x  '45 

Width  of  space  =     .,      x  -55 
Play  =     „      x  -10 


Length  beyond  pitch  line  =  pitch  x  -35. 

Common  Proportion  of  Keys.    (Unwiu.) 

Diameter  of  eye  of  wheel  or  boss  of  shaft  =  d 
Width  of  key  =  1>  =  \d  +  £ 
Mean  thickness  of  sunk  key  =  t  =  \d  +  J 
„  „  key  in  flat  =  ?i=  fal  +  -,!„ 


188 


GAS   ENGINEER  8   POCKET-BOOK. 


In  toothed  wheels  T.  of  tooth  =  -48  pitch. 
Width  of  space  =  '3  pitch. 
Height  above  pitch  line  =  '3  pitch. 
Depth  below  pitch  line  =  '4  pitch. 

A  good  new  leather  belt  has  a  tenacity  of  from  3,000  to  5,000  lbsc 
per  square  inch  of  section. 

Coefficient  of  friction  is  about  '423  between  ordinary  belting  and 
cast  iron  pulleys. 

If  leather  belting  has  a  tenacity  of  1,000  Jbs.  per  inch  of  width  the 
strength  of  a  riveted  joint  may  be  taken  at  400  Ibs.,  a  butt-laced 
joint  at  250  Ibs.,  and  an  ordinary  overlapped  laced  joint  at  470  Ibs. 

Effective  working  stress  of  ordinary  single  belts          50  Ibs. 
„  „  light  double  70     „ 

,,  „  heavy  double        „  90     „ 

Diameter  of  pulley  should  be  more  than  100  times  the  thickness  of 
the  belts  around  it.  Ratio  between  two  pulleys  ought  not  to  exceed 
6  to  1.  Convexity  of  pulleys  equals  J  inch  per  foot  in  width. 

Centrifugal  action  on  belts  may  be  ignored  at  ordinary  speeds  up  to 
3,000  feet  per  minute. 

Internal  friction  in  ropes  driving  pulleys  is  the  principal  destructive 
agent. 

Breaking  strain  of  good  icpes  =  4  tons  per  square  inch. 
Working  „  „  =  300  Ibs.  per  square  inch. 

Ropes  should  not  be  driven  above  4,700  feet  per  minute. 

Cotton  appears  to  be  best  for  driving  pulleys. 

It  is  said  that  belts  should  be  made  heavier  and  run  more  slowly 
than  ordinary  rules  state  to  save  cost  in  long  run  and  prevent 
stoppages  for  relacing  and  repairing.  At  intervals  of  three  months 
each  belt '-should  be  scraped  cle:m  and  dubbed. 


Working  Tension  of  Belts  (Leather). 


Thickness  of  Belt 

(in  Inches)  .    . 

T3H 

A 

} 

T5« 

f 

™ 

* 

ft 

i 

tt 

i 

Tension   in   Lbs. 

p§r  Inch  Width 

GO 

70 

80 

100 

120 

140 

160 

180 

200 

220 

24o 

Single. 

Double. 

Usual  Proportions. 


Width  of  Belt  (in  Inches)  . 

2 

3 

4 

6 

8 

10 

12 

15 

Thickness  (Inch)  .     .     .     . 

0-14 

•17 

•20 

•24 

•28 

•32 

•35 

•3D 

Working  Tension  in  Lbs. 

per  Inch  of  Width     .     . 

45 

55 

64 

78 

90 

101 

110 

124 

ROPE    GEARING. 


189 


Horse-power  of  different  sized  Manilla  Ropes  at  different  speeds 
Working  stress  =  ^th,  breaking  stress  =  Jfeth  strength  of  splice. 
Horse-powers. 

5  10  15  20  25  30  35  40  45 

ISO 


140 


130 


„ 


a     70 

* 

1     60 


10  20  25  30  35  40  45 

Horse-powers. 


190 


GAS  ENGINEER'S  POCKET-BOOK. 


Width  of  Belts  in  Inches  when — 


Velocity 
of  belt  in 
Ft.  per  Sec. 

The  Horse-power  Transmitted  is 

1 

2 

0 

4 

5 

»l 

10 

15 

20 

25 

1 

15-7 

31-4 

47-0 

63-0 

2* 

6-3 

10-6 

18-8 

25-2 

31-2 

46-8 

5 

3-1 

6-3 

9-4 

12-6 

15  c, 

23-6 

31-4 

47-2 

H 

2-1 

4-2 

6-3 

8-4 

10-4 

15-6 

21-0 

31-2 

42-0 

52-4 

10 

1-5 

3-2 

4-7 

r,-4 

:•> 

11-8 

15-7 

23-6 

31-4 

39-2 

12i 

1-3 

2-5 

3-7 

5-0 

6-4 

9-4 

12-6 

18-8 

25-2 

31-2 

15 

1-1 

2-1 

3-1 

4-2 

5-2 

7-8 

10-5 

15-6 

21-0 

26-2 

20 

•79 

1-6 

2-4 

3-2 

3-9 

5-9 

7-9 

11-7 

15-7 

19-6 

25 

•63 

1-3 

1-9 

2-6 

3-1 

4-7 

6-3 

9-4 

12-6 

15-6 

30 

1-1 

1-6 

2-2 

2-6 

3-9 

5-2 

7-8 

10-5 

13-1 

35 

1-3 

1-7 

22 

3-4 

4-5 

6-8 

9-0 

11-2 

40 

1-5 

2-0 

2-9 

3-9 

5-9 

7-8 

9-8 

45 

1-8 

2-6 

3-5 

5-2 

7-0 

8-8 

50 

1-fi 

2-4 

3-2 

4-7 

0-3 

7-8 

60 

1-3 

2-0 

2-fi 

3-0 

5-2 

6-5 

70 

1-1 

1-7 

2-2 

3-4 

4-5 

5-6 

80 

1-5 

2-0 

2'1» 

3-9 

4-9 

90 

1-3 

1-8 

2-6 

3-5 

4-4 

100 

1-2 

1-fi 

2-4 

3-1 

3-9 

Thickness  of  belt — inch. 


(Unwin.) 


Modern  Gas  Engines. 

Compression  of  charge  =  89  to  90  Ibs.  per  square  inch. 

Initial  pressure  at  moment  of  explosion  =  300  Ibs.  per  square  iivSi 

Consumption  per  effective  horse-power  =  16-48  cubic  feet. 

Actual  efficiency  =  28'26  per  cent. 

Mechanical  efficiency  =  86  per  cent. 

Fuel  consumption  per  I.H.P.  =  0'8  Ib.  anthracite  coal. 

Gas  Engines. — The  consumption  of  gas  is  now  under  16£  cubic  feet 
per  horse-power.  The  governors  of  gas  engines  control  the  valve 
that  admits  gas  to  the  cylinder.  When  the  speed  is  low  gas  is 
admitted,  and  an  explosion  puts  new  energy  into  the  flywheel ; 
when  the  speed  is  high,  no  gas  is  let  in  and  no  explosion  takes  place. 
Ignition  is  chiefly  by  means  of  a  Bunsen  flame  in  England,  and  by 
electric  spark  on  the  Continent. 

In  the  "  Otto  "  cycle  gas  engines  the  gas  and  air  are  drawn  in  by  a 
forward  motion  of  the  piston,  on  the  return  stroke  it  is  compressed, 
at  the  commencement  of  the  next  forward  stroke  it  is  ignited  and  the 
piston  is  moved  forward,  the  return  stroke  expelling  the  products  of 
combustion. 

Modern  gas  engines  of  best  type  compress  the  charge  to  from  40 
to  6Q  Ibs.  per  square  inch  before  ignition. 


GAS   ENGINES.  191 

Mean  effective  pressure  in  "  Otto"  cycle  gas  engines  =  50 to  GOlbe. 
per  square  inch. 

Gas  engines  of  100  brake  horse-power  and  upwards  are  now  made  to 
consume  not  more  than  20  cubic  feet  of  town  gas  per  horse-power 
per  hour  at  full  load. 

Experiments  made  show  that  the  deleterious  effect  of  burnt  gases 
is  much  overrated  in  the  case  of  coal  gas  products  in  gas  engines. 
(F.  Grover.) 

Consumption  per  brake  horse-power  per  hour  at  half  load  with 
gas  or  steam  engines  is  about  40  per  cent,  more  than  at  full  load. 

Gas  Engines. 

Cubic  Feet  Gas 
B.  H.  P.  per  B.  H.  P.  Hour. 

Simplex       .         .         .  8'79  .         .        .  20-38 

Atkinson  Cycle        .     .  4-89  .         .     .  22-5 

Forward      .         .         .  4-8  .         .  23-97 

Otto  Crossley .         .     .  14-7  .         .     .  241 

Atkinson's  Differential  2-6  .         .  25-7 

Griffin     ....  12-5  .         .     .  28-5 

Clerk's  Eiigiiu    .        .  7-2  .        .        .  30-4 

Horse-power  of  Gas  Engine. — The  indicated  horse-power  is  equal 
to  the  mean  effective  pressure  in  pounds  per  square  inch  multiplied 
by  the  length  of  the  stroke  in  feet  by  the  area  of  the  piston  in  square 
inches  and  by  the  number  of  explosions  per  minute,  and  divided  by 
33,000. 

Gas  engine  diagrams  prove  that  the  rise  in  pressure  which  takes 
place  in  the  gas  engine  through  the  gas  exploding  at  the  dead  point 
relatively  slowly  is  not  more  rapid  than  that  which  occurs  on  the 
admission  of  high-pressure  steam  to  the  steam  cylinder. 

Mechanical  efficiency  of  a  gas  engine,  about  80  to  85  per  cent. 

Gas  engines  can  be  run  to  within  3  to  4  per  cent,  of  the  normal 
rate. 

Temperature  in  cylinder  of  gas  engines,  2,500°  F.  to  3,000°  F. 

The  work  expended  in  compressing  gas  does  not  increase  pro- 
portionally with  the  pressure,  but  is  relatively  much  less  with  high 
pressures. 

Average  gas,  1  to  8  to  12  of  air  in  gas  engine. 

Only  2J  times  the  power  is  needed  to  increase  a  pressure  of  10 
atmospheres  tenfold — i.e.,  to  raise  it  to  100  atmospheres. 

A  good  steam  engine  develops  one  I.H.P.  per  kilogramme  coal  of  a 
calorific  power  of  8,500  calories. 

A  cubic  metre  of  gas  develops  5,300  calories,  and  one  I.H.P.  in  a  gas 
engine  with  a  thermal  duty  of  50  per  cent,  in  favour  of  the  gas  engine. 
(Hirsh.) 

Exhaust  pipes  from  gas  engines  should  have  easy  bends. 

At  ordinary  atmospheric  pressure  and  temperature  mixtures  of  gas 
and  air  will  not  ignite  explosively,  if  at  all,  when  the  air  amounts  to 
about  fourteen  times  the  bulk  of  a  given  quantity  of  gas,  and  similarly 
the  mixtures  will  not  ignite  explosively  if  too  much  gas  be  present. 


192  GAS  ENGINEER'S  POCKET-BOOK. 

One  pound  of  a  mixture  of  oxygen  and  coal  gas  in  the  proportions 
required  for  complete  combustion  would  upon  ignition  develop  about 
the  same  energy  as  3^  Ibs.  of  gunpowder. 

With  coal  gas  at  3*.  per  1,000  cubic  feet  and  coal  at  15*.  per  ton 
the  gas  engine  consuming  20  feet  per  I.H.P.  per  hour  =  a  steam 
engine  consuming  9  Ibs.  of  coal  per  I.  H.P.per  hour.  (T.  L.  Millar.) 

With  lighting  gas  the  cost  of  running  large  gas  engines  is  about  tfce 
same  as  for  steam  engines,  lighting  gas  being  much  dearer  than 
generator  gas  for  power  purposes,  especially  for  engines  above  12  H.P. 

Gas  consumption  in  Dessau  tramcars  worked  by  gas  engines  =  31 -2 
cubic  feet  per  mile  run.  including  loss  in  compression,  which  is  very 
little.  (Herr  von  Oechelhauser.) 

Gas  Engines  for  Tramcars. — An  8  H.P.  engine  (Otto  type)  :  charge 
of  compressors  =  8  miles  supply,  cost  =  Id.  per  mile  for  gas. 

From  4  to  6  gallons  water  are  required  per  I.H.P.  to  cool  gas  engine 
cylinders. 

In  cooling  the  cylinders  of  gas  engines  35  per  cent,  of  the  thermal 
units  in  the  gas  are  lost. 

Capacity  of  circulating  tanks  should  equal  23  to  30  gallons  per 
I.H.P. 

To  Find  Size  of  Dry  Meter  for  Gas  Engines. 

Brake  horse-power  x  3'4  -f-  5  =  number  of  lights. 
The  size  of  supply  pipe  to  engine  can  be  found  by  reference  to  table 
of  meter  dimensions. 

To  Find  Size  of  Exhaust  Pipe. 

From  1  to  5  brake  horse-power,  1  inch  to  If  inches  diameter. 

Above  that  size,  diameter  in  inches  =  0-528  X  H.P.0'57. 

The  heat  of  exhaust  pipes  is  great,  and  likely  to  burn  wood  if  too 
near.  Bends  of  6  inches  or  more  radius  only  should  be  used  ;  no 
elbows  or  tees.  Turn  the  outlet  of  the  pipe  to  look  downwards. 

To  Prevent  Excessive  Noise  in  Exhaust  Pipe. 

The  pipe  can  be  carried  into  a  drained  pit  and  surrounded  with 
stones,  over  which  a  covering  of  straw  can  be  placed. 

Quantity  of  Water  Required  for  Cooling  Cylinder. 

About  5  gallons  per  I.H.P.  per  hour  if  taken  direct  from  mains, 
and  led  to  under  side  of  jacket  at  clearance  end  of  cylinder,  and 
removed  from  upper  side  at  the  opposite  end.  If  hard  water  is  used, 
add  a  handful  of  washing  soda  to  tank  every  month. 

Circulating  Tank's  Capacity. 

Twenty  to  30  gallons  per  I.H.P.  with  pipes  from  1  inch  to  3  inches 
diameter,  according  to  size  of  engine.  The  return  pipe  is  usually  a 
little  larger  than  the  flow,  with  a  rise  of  at  least  2  inches  per  foot 
leading  to  the  tank  at  the  normal  water  level. 


GAS    ENGINES. 


193 


Value  of  Explosive  Mixtures.     (Dugald  Clerk.) 


Mixture. 

Maximum  Pressure 

of  Explosion  above 
Atmosphere  in  Ibs. 
per  Square  Inch. 

Time  of  Explosion. 

Gas. 

Air. 

1  vol. 

13  vols. 

52 

0-28  second. 

1     „ 

11      „ 

63 

0-18       „ 

1     » 

9     „ 

69 

0-13       „ 

1     „ 

7     „ 

89 

0-07      „ 

1     „ 

5     „ 

96 

0-05       „ 

Temperature  before  explosion,  64°  F.  Pressure  before  explosion, 
atmospheric. 

Examine  the  ignition  tube  occasionally  to  see  that  no  soot  has 
been  deposited  by  the  Bunsen  flame. 

Before  starting  compress  the  gas  bag  and  then  turn  on  gas,  turning 
the  engine  meanwhile  to  remove  the  air  which  may  have  accumulated 
in  the  gaspipes. 

To  stop  the  engine  shut  the  gas-cock  near  cylinder — not  at  the 
meter. 

The  ratio  of  heat  converted  into  work  in  a  gas  engine  is  greater 
than  in  a  steam  engine. 

Average  heat  units  lost  in  the  jacket  or  cooling  water,  35  per  cent. 
„  ,,  „  „  „  exhaust,  37  per  cent. 

Otto  or  Four-Cycle  Gas  Engines. — An  explosion  takes  place  every 
four  strokes,  or  one  per  double  revolution  of  the  crank  shaft,  viz., 
piston  advances,  drawing  in  the  explosive  charge  ;  it  then  returns, 
compressing  the  mixture  ;  next  ignition  takes  place,  the  piston  is 
driven  forward,  and  on  retiring  finally  expels  the  waste  products  of 
combustion. 

The  consumption  of  ordinary  illuminating  gas  in  modern  gas 
engines  equals  from  20  to  26  cubic  feet  per  I.H.P.  per  hour  for 
moderate  to  small  powers,  and  for  larger  powers  18  to  as  low  as  15 
cubic  feet  has  been  obtained,  and  with  the  compound  type  as  low 
as  10.  This,  if  supplied  with  Dowson  gas,  means  only  '8  Ibs.  of  coal  per 
I.H.P.  per  hour.  The  mechanical  efficiency  may  be  taken  as  from 
80  to  85  per  cent,  at  full  power,  and  from  70  to  75  per  cent,  at  half 
power. 

Messrs.  Crossley  state  that  with  town  gas  at  3*.  per  1,000  the 
working  cost  of  a  gas  engine  of  14  horse-power  nominal  and  up- 
wards is  greater  than  that  of  a  steam  engine. 

It  has  been  proved  that  by  scavenging  the  power  of  a  gas  engine 
can  be  increased  10  per  cent.,  or  the  consumption  of  gas  reduced, 
keeping  the  power  the  same. 

With  coal  gas  it  is  a  moot  point  if  the  products  of  combustion  hurt 
the  next  charge  in  gas  engines. 

Gas  engines  are  most  economical  at  full  power. 

G.E.  O 


194 


GAS  ENGINEER'S  POCKET-BOOK. 


A  speed  test  made  with  a  Moscrop  recorder  on  a  single-cylinder 
double-acting  "  Kilmarnock  "  Otto  cycle  engine  showed  a  variation 
of  2|  per  cent,  at  powers  varying  from  normal  full  load  down  to 
one  third. 

Value  of  Coal  Gas  of  Different  Candle  Powers  for  Motive  Power. 
(C.  Hunt.) 


Candle  Power. 

Consumption  Cubic 
Feet  per  I.H.P. 

Relative  Value  for 
Motive  Power. 

Relative  Value  for 
Lighting. 

11-96 

30-31 

i-ooo 

1-000 

15-00 

24-41 

1-241 

1-254 

17-20 

22-70 

1-335 

1-438 

22-85 

17-73 

1-709 

1-910 

26-00 

16-26 

1-864 

2-173 

29-14 

15-00 

2-020 

2-436 

Oil  Engines. 

The  oil  consumed  per  hour  equals  from  -7  Ib.  with  American  oil 
to  -86  Ib.  with  Kussian  per  indicated  horse-power. 

A  Priestman  oil  engine,  using  oil  above  75°  F.  flashing  point, 
developed  1  brake  horse-power  per  1-25  Ib.  oil.  (W.  Anderson.) 

In  a  Priestman  oil  engine  tested  by  Professor  Unwin— 

•69  and  -86  Ib.  oil  used  per  I.H.P. 
•84    „     '94    „        „        „     B.H.P. 

Thermal  efficiency  13-31  per  cent.  Loss  of  heat  in  cooling  water 
47-54  per  cent.  Mechanical  efficiency  82  to  91  per  cent.  Loss  of 
heat  in  exhaust  gases  26-72  per  cent. 


To  find  Leaks  in  connections  under  Suction. 

By  fixing  a  small  governor  on  the  byepass  of  the  exhauster, 
weighted  to  2  inches,  a  pressure  will  be  thrown  on  the  plant  up 
to  the  hydraulic,  any  leaks  showing  themselves  and  explosions 
prevented. 


SCRUBBERS   AND   WASHERS.  195 


SCRUBBERS  AND  WASHERS. 

Herr  Reissner's  Rule 5  cubic  feet  to  6  cubic  feet  per  1,000  cubic 

feet  per  24  hours  of  scrubbers. 

Wyatt's  Rule. — 100  cubic  feet  internal  capacity  of  vessels  (scrubbers 
and  washers)  with  a  gas  contact  of  from  15  to  27  minutes  per  ton 
per  diem.  Gas  in  scrubbers  should  equal  1  per  cent,  of  the  maximum 
daily  make  to  give  requisite  contact  time. 

Horizontal  net  sectional  area  of  all  the  scrubbers  is  2  square  feet 
per  ton  per  day  maximum  make. 

Capacity  of  scrubbers  should  be  15  cubic  feet  per  1,000  feet  of  gas 
per  diem,  the  vessel  being  one  third  the  diameter  of  its  height. 
(Kichards.) 

Another  Rule. — Scrubbers  should  be  equal  to  allowing  a  contact 
for  10  to  15  minutes  of  greatest  make.  Height  is  an  advantage,  so 
that  the  gas  may  be  easier  broken  up  and  wetted  surfaces  presented. 

Tower  scrubbers  usually  6  or  7  times  the  diameter  high. 

Scrubbers  should  be  cylindrical.  Height  equal  to  6  or  7  times 
the  diameter.  Capacity  equal  to  9  cubic  feet  per  1,000  cubic  feet 
per  diem  maximum  make.  (Herring.) 

Newbigging's  Rule  for  tower  scrubbers,  9  cubic  feet  per  1,000  cubic 
feet  gas  made  per  day. 

The  washer  or  scrubber  wherein  the  gas  is  broken  up  into  small 
streams  passing  in  contact  with  wetted  surfaces  is  preferable  to  that 
in  which  the  water  is  divided  into  small  drops  and  which  fall  through 
the  gas,  as  the  bulk  of  the  gas  is  at  least  100  times,  and  more  often 
1,000  times,  that  of  the  liquid. 

A  good  scrubber  should  so  distribute  the  water  or  liquor  that  the 
whole  of  the  surfaces  exposed  to  the  gas  in  its  passage  should  be 
evenly  wetted,  with  length  of  contact  and  such  contact  ensured. 

The  use  of  a  washer  requiring  a  separate  engine  must  be  compared 
with  the  extra  cost  of  the  fuel  required,  in  one  throwing  some  3  or 
4-  inches  pressure  upon  the  exhauster. 

Scrubbers  filled  with  coke  will  collect  tar  and  cause  a  lowering  of 
illuminating  power  by  absorption  of  light-giving  hydrocarbons. 

When  coke  is  used  in  a  tower  scrubber  a  space  of  6  inches  is 
usually  left  above  each  layer  before  the  next  tier  of  sieves. 


Average  Surface  presented  to  Gas  in  Scrubbers. 

When  filled  with  coke     .        .        .    *3    or  8|  sq.  feet  per  cubic  foot. 
„         3-inch  drain  pipes    -54  „  17     „  „  „ 

9  «fifi         91 

55  »  •         55  »  >'  '°     !)     **          >5  »  J) 

boards         .        .  TOO  „  31     „ 

Scrubber  Boards  should  be  £  inch  thick  with  f  inch  or  £  inch  space 
between. 

Boards  11  inches  deep,  £  inch  thick,  set  f  inch  apart,  are  used  in 
tower  scrubbers  with  success. 

o? 


196 

Ten  volumes  of  water  at  60°  F.  and  30  inches  pressure  will 
absorb — 

7,800     volumes  ammonia. 
25'3  .         sulphuretted  hydrogen. 


10-0 
1-25 
•37 
•156 
•156 
•156 
•160 


carbonic  acid. 

defiant  gas  and  probably  other  hydrocarbons, 

oxygen. 

carbonic  oxide. 

nitrogen. 

hydrogen. 

light  carburetted  hydrogen. 


When  water  has  been  saturated  with  one  gas  and  is  exposed  to 
the  influence  of  a  second  it  usually  allows  part  of  the  first  absorbed 
to  escape,  while  an  equivalent  quantity  of  the  second  takes  its  place. 

Thus  a  large  volume  of  an  easily  soluble  gas  can  be  expelled  by  a 
small  quantity  of  a  difficultly  soluble  one.  (Dr.  Frankland.) 

Liquor  distributers  sometimes  fixed  half  way  up  scrubbers  where 
only  one  scrubber  is  in  use. 

The  whole  of  the  ammonia  can  be  removed  from  the  gas  in  practical 
working  by  using  3  gallons  water  per  ton  of  coal  carbonised,  and  the 
quantity  of  NH3  per  1,000  cubic  feet  need  not  exceed  "3  to  '4  grains 
at  the  outlet  of  the  clean  scrubber. 

Quantity  of  water  required  in  tower  scrubbers  from  10  to  18  gallons 
per  10,000  cubic  feet  gas  made. 

When  more  than  one  washer  is  used  the  liquor  should  be  made  to 
flow  from  the  one  the  gas  enters  last  through  to  the  first,  so  that  the 
gas  meets  the  stronger  liquor  first. 

Provide  byepasses  to  all  the  different  parts  of  the  works. 

Washers. 

About  28  gallons  of  liquor  of  10  oz.  strength  can  be  obtained  from 
1  ton  Newcastle  coal. 
Reaction  of  cyanides  (Prussian  blue)  :  — 


6NH4CN  4  446  42 

3NH4Fe(CN)6  +  2Fe2Cl6  =  3Fe"Cya,2Fe'"aCy6 
orFe7Cy1Q  +  12AmCl. 

Pressure  thrown  by  washers  varies  from  1  to  4  inches. 


PURTFIERS.  197 


PURIFIERS. 

In  fixing  upon  size  of  purifiers  note  should  be  taken  of  the  quality 
of  coal  likely  to  be  used  for  manufacturing  gas.  Some  Midland  coals 
produce  gas  containing  nearly  double  the  amount  of  H2S  which  is  to 
be  found  in  Newcastle  coal.  Have  the  purifiers  large  enough  is  an 
excellent  rule. 

Scotch  coals  produce  large  quantities  C02. 

Clegg's  Rule  for  Area  of  Purifiers.— 1  foot  area  per  3,600  cubic  feet, 
maximum  make,  per  diem. 

Hughe  ^  Rule  for  Area  of  Purifiers. — 1  square  yard  sieve  per  1,000 
subio  feet,  maximum  make,  per  diem. 

Newbigging's  Rule  for  Area  of  Purifiers. 

Maximum  daily  make  x  6 

=  square  feet  area  each  purifier. 

Newbigging's  Rule  for  Area  of  Purifiers  Connections. 


Inches,  diameter  =  ^/area  of  purifiers  in  feet 

For  large  purifiers  deduct  one-eighth. 

Beckton  practice  :  1  square  foot  of  purifier  area  per  2,500  cubic 
feet  made  per  diem. 

Allow,  say,  1  square  yard  of  active  grid  per  1,000  feet  of  gas  per  day. 

Sulphur  purification  requires  for  2,000,000  plant  8  boxes  32  feet  x  32 
feet  X  6  feet  deep,  with  4  trays  for  lime  and  3  for  oxide  —  1  cubic  foo: 
contents  of  each  purifier  per  each  376  cubic  feet  per  diem.  (A.  Colson..) 

Purifying  shed  for  above,  320  feet  x  60  feet.     (A.  Colson.) 

Rate  of  passage  of  gas  through  lime  purifiers  should  not  exceed 
2,000  cubic  feet  per  foot  of  surface  per  24  hours.  (G.  Anderson.) 

Purifiers  (where  lime  only  is  used  and  no  sulphur  clauses)  should 
allow  a  contact  of  15  minutes  of  greatest  make,  or  cubical  contents 
=  ^  hour's  make,  with  5  tiers  lime,  each  2J  inches  thick. 

C.  Hunt's  Rule  for  Area  of  Each  Purifier  in  a  series  is  not  less  than 
O'l  square  foot  for  every  £  per  cent,  by  volume  of  the  maximum 
quantity  of  C02  experienced.  C02  varies  from  1£  to  over  3  per 
cent. 

Lime  and  oxide  purifiers  when  worked  in  conjunction  require  from 
20  to  30  square  feet  per  ton.  (C.  Hunt.) 

G.  C.  Trewby's  Rule.— 320  feet  for  each  vessel  per  1,000,000  cubic 
feet  of  daily  manufacture. 

Four  feet  area  per  box  per  ton  of  coal  carbonised  per  day  with  6 
purifiers  in  the  series,  4  for  lime  and  2  (catch)  for  oxide.  (F.  Livesey.) 

Wyatt's  Rule.— 100  superficial  feet  of  sieves  per  ton  per  day  1,620 
cubic  feet  to  house  the  purifiers  with  a  floor  area  of  50  square  feet  per 
ton  per  diem,  133  cubic  feet  total  capacity  of  vessels,  gas  contact  of 
15  to  27  minutes,  area  of  covers  of  purifiers  3  square  feet  per  ton  per 
diem. 


198 


GAS  ENGINEER'S  POCKET-BOOK. 


Lime  and  oxide  sheds  :  810  cubic  feet  of  building  structure  floors 
area  of  25  square  feet  per  ton  per  diem. 

Wyatt's  Eule. — 33  cubic  feet  or  50  superficial  feet  per  ton  per  day, 
contact  time  5  to  8  minutes. 

The  useful  surface  for  passage  of  gas  should  be  £rd  the  volume  of 
the  oxide,  time  of  contact  48  seconds,  bulk  should  equal  -^th  of  the 
gas  passed  per  hour,  with  1  layer  24  inches  thick  ;  material  showed 
15-65  per  cent,  total  sulphur  and  11'75  per  cent,  free  sulphur,  while 
with  4  layers  each  6  inches  thick  it  showed  14'96  and  9'03  per  cent, 
respectively.  (Messrs.  Delseaux  and  Renard.) 

In  the  Beckton  method  of  8  purifiers  an  area  of  0'4  foot  per  1,000 
cubic  feet  of  gas  per  vessel  is  sufficient.  (L.  T.  "Wright.) 

Allow  half  a  square  foot  per  1,000  cubic  feet  maximum  daily  make 
for  area  of  each  purifier.  (Herring.) 

Purifying  surface  may  range  from  1-3  to  4  square  feet  per  1,000 
cubic  feet  gas  per  day. 

Area  of  each  purifier  should  equal  676  square  feet  per  million  per  day. 

Speed  of  gas  through  purifiers  should  be  as  slow  as  possible. 

Herr  Eeissner's  Eule. — Purifiers.  Five  trays  with  oxide  in  each, 
1'17  square  feet  area  per-1,000  cubic  feet  in  24  hours  if  4  purifiers, 
all  included  in  above.  Catch  purifier  with  4  to  6  trays  sawdust. 

Use  purifiers  of  large  area  :  with  lime,  2  to  4  tiers  of  sieves  with 
layer  of  lime  6  to  9  inches  thick  ;  with  oxide,  2  or  3  tiers  of  sieves 
with  layer  of  oxide  18  inches  deep  on  each. 

Purifiers  (construction  notes).— Thickness  of  cast  iron  purifier 
plates  should  never  be  less  than  |  inch.  The  usual  width  of  same 
f>  feet.  Flanges  of  bottom  plates  should  be  2|  inches  x  f  inch  over 
and  above  the  thickness  of  plate. 

Strong  and  deep  brackets  should  be  fixed  under  lute,  as  strain  is 
greatest  at  this  point.  (F.  S.  Cripps.) 

Cast  iron  plates  for  purifiers,  if  made  larger  than  5  feet  by  5  feet, 
are  liable  to  twist  in  casting.  Flanges  should  not  be  less  than  3  inches 
deep,  and  thickness  about  £  inch  to  I  inch  ;  plates  £  inch  thinner. 

Depth  of  water  lute  in  purifiers  varies  from  12  inches  in  small 
purifiers  to  30  inches  in  larger  ones  ;  width  from  4J  inches  to 
8  inches. 

Seals  of  purifiers  should  never  be  less  than  18  inches  deep. 

Diameter  in  inches  of  pipes  in  connections  to  purifiers  should  equal 
the  square  root  of  area  of  purifiers  in  feet. 


Arrangements  of  Purifier  Connections.    (Dempster.) 


PURIFIER    CONNECTIONS.  199 

Arrangements  of  Purifier  Connections.     (Dempster) — continued. 


F 

5  JxM  :  1 

o-J 

0- 

a 

—  i 

0 

1 

E 

3 

E 

^ 

r-zs 

ol 

C 

i 

01         . 

5 

21 

ol  .    9 

r 

tHJ 

200  GAS  ENGINEER'S  POCKET-BOOK. 

Arrangements  of  Purifier  Connections.     (Dempster) — continued. 


Flanges  of  purifier  plates  should  be  planed  (not  necessarily  the 
whole  width,  a  strip  |  inch  or  f  inch  wide  each  side  and  at  ends 
being  sufficient),  a  layer  of  vulcan  cement  or  red  and  white  lead  being 
put  into  the  joint  before  it  is  bolted  up.  The  alternative  method  is  to 
have  a  fillet  cast  on  inside  of  flange  and  the  joint  caulked  with  iron 
borings  and  sal-ammoniac  and  sulphur. 

It  is  usual  to  keep  purifiers  and  gasholders  away  from  retort 
houses  to  avoid  chances  of  lighting  up  at  escapes  or  explosions. 

Fastenings  to  purifiers  should  be  strong  enough  to  resist  pressure, 
equal  to  a  column  of  water  the  height  of  the  depth  of  lute,  upon  the 
whole  area  of  the  cover,  the  weight  of  cover  causing  the  gas  to  blow 
the  water  from  the  lute, 


CLAUS   PROCESS.  201 

Valves  or  ground  plugs  should  be  provided  for  permitting  the  air 
to  enter  while  the  cover  is  lifted,  and  should  at  least  equal  one-third 
the  diameter  of  the  connections  to  the  purifiers. 

Side  sheets  of  purifier  covers  should  be  made  thicker  than  the  top 
sheets,  as  the  level  of  the  surface  of  the  water  is  where  the  plates 
will  first  rust. 

Crown  sheets  may  be  of  No.  12  Birmingham  wire  gauge. 

Purifiers  in  the  open  can  be  kept  warm  in  winter  by  the  use  of  hay 
or  straw,  and  cool  in  summer  by  spraying  water  over  the  covers. 

If  the  top  of  the  purifiers  are  kept  18  inches  above  ground  the 
material  can  be  easily  removed  and  wheeled  in. 

Lifting  of  purifiers  is  best  done  by  straps  at  the  sides  of  the  covers. 

Purifier  sieves  usually  made  2  inches  thick  with  f-inch  taper  deal 
bars,  and  distance  blocks,  oak  side  strips  1£  inch  by  2  inches,  and 
fastened  by  f-inch  bolts  or  rivets. 

Usual  thickness  of  layers. — Oxide,  2  feet  6  inches  deep  ;  lime,  1  foot 
deep. 

About  701bs.  quicklime  will  remove  C02  per  1  ton  coal. 

Oxide  heated  to  70°  C.  revivifies  easier. 

Lime  should  be  sulphided  below  40°  F. 

135  gallons  water  required  per  cubic  yard  dry  lime,  making  2\  yards 
slaked  material. 

One  cubic  yard  kiln  lime  weighs  11  cwts. 

Mr.  W.  King  has  erected  a  purifier  house  without  valves — U  tubes, 
which  can  be  filled  with  water  to  prevent  the  passage  of  the  gas,  being 
used. 

The  Glaus  Ammonia  Process  of  Purification. — The  gas,  having  passed 
through  a  tar  extractor,  is  then  passed  through  several  scrubbers  filled 
with  broken  ganister  bricks,  and  here  meets  ammonia  gas,  and  in 
the  first  two  scrubbers  ammoniacal  liquor  freed  from  C02  and  H2S, 
the  gas  being  entirely  freed  in  its  passage  from  C02  and  H2S. 
while  of  ammonia  there  remains  at  the  outlet  of  the  last  scrubber 
only  the  usual  faint  traces,  and  the  bisulphide  of  carbon  is  reduced  by 
from  20  to  70  per  cent.  Arrangements  are  made  that  in  5  towers  the 
scrubber  liquor  is  heated  to  a  carefully  regulated  temperature  for  the 
purpose  of  driving  off  the  CO2  and  H2S  with  as  little  loss  as  possible 
of  ammonia.  It  is  then  passed  through  3  more  towers,  in  the 
second  of  which  it  is  exposed  to  free  steam,  which  deprives  it  of  all 
traces  of  C02  and  H2S,  and  also  of  all  ammonia,  except  what  may 
be  present  as  fixed  in  the  form  of  sulphocyanide  of  ammonium  ;  in 
the  third  tower  the  hot  vapours  (187°)  are  condensed  .to  120°  or  less, 
and  are  then  ready  for  use  again  to  remove  the  impurities.  All  the 
sulphur  gases  driven  off  from  the  liquor  are  deposited  in  a  chamber 
in  the  form  of  pure  sulphur,  equal  to  from  10  Ibs.  to  141bs.  per  ton  of 
coal  used. 


202  GAS  ENGINEER'S  POCKET-BOOK. 


GASHOLDER   TANKS. 

As  a  general  rule  the  bearing  capacity  of  grou 
the  surface  is  greater  than  at  the  surface  itself,  but  in  all  cases  bore- 
holes should  be  made  to  see  that  the  solid  ground  upon  which  it  is 
proposed  to  lay  the  bottom  of  the  tank  is  fairly  level,  and  that  it  is  of 
sufficient  depth.  In  some  cases  the  strata  of,  say,  ballast,  which  would 
safely  carry  the  tank  walls,  &c.,  have  been  cut  through,  or  nearly  so, 
and  when  the  tank  has  been  completed  the  level  of  the  walls 
has  varied  considerably. 

The  larger  the  number  of  the  borings  taken  around  a  proposed  gas- 
holder tank  site  the  better  to  ensure  that  the  foundation  is  level  and 
equally  weight-resisting. 

If  any  doubts  exist  as  to  the  solidity  of  the  ground  where  the  tank 
is  proposed  to  be  placed  it  is  better  to  put  up  an  iron  or  steel  one, 
which  may  be  made  to  rest  on  piles  and  cross  timbers. 

It  is  often  better  to  raise  the  level  of  the  wall  of  the  tank  when 
water  is  found  in  the  subsoil  which  may  afterwards  injure  the  nature 
of  the  foundation. 

For  tanks  up  to  36  feet  deep  and  inside  diameters  of  150  feet  : 
ith  the  depth  of  tank  =  thickness  of  concrete  walls, 
ith          „  „        =  „  piers, 

ith          „  „         =  width  of  piers. 

(Wyatt,  30th  April,  1889.) 

The  well  or  sump  which  is  sunk  before  commencing  a  tank  may  be 
lined  with  steining  (open  brickwork  without  mortar),  or  merely 
timbered  with  stout  timbers  if  it  is  proposed  to  fill  up  the  sump  when 
the  tank  is  completed.  In  some  cases  large  pipes  (cast  iron)  have 
been  let  in  as  the  excavation  proceeded,  without  jointing,  and  thus 
formed  an  excellent  backing  to  prevent  the  sides  falling  in. 

The  sump  should  be  at  least  3  to  5  feet  deeper  than  the  lowest  part 
of  the  excavation  to  be  made  for  the  tank  ;  often  a  considerable 
amount  deeper  will  lessen  the  after  expense  with  tanks  in  bad 
ground. 

Sometimes  more  than  one  sump  is  found  necessary,  or  drain  pipes 
have  to  be  laid  to  convey  the  water  to  the  pumps,  which  should 
always  be  in  duplicate. 

Natural  Slopes  of  Earths  with  the  Horizontal  Line  or 
Angles  of  Repose. 

Gravel  average 40  degrees  or  1*2    to 

Dry  sand  average 38  or  1-30  to 

Sand  average 22  or  0'27  to 

Vegetable  earth  average       ...     28  or  1-89  to 

Compact  earth  average     .         .         .     .     50  or  0'7    to 

Shingle  average 39  or  1-25  to 

Rubble  average         .        c        .        .     .    45  or  1-0    to 

Clay,  well  dried,  average  «.  .  .45  „  or  1-0  to 
Clay,  wet,  average  .  .  .  .  .  16  „  or  8-3  to 
Peat  average 28  „  or  1 '89  to  1 


GASHOLDER    TANKS.  203 


General  Tank  Notes. 

An  Iron  or  Steel  Tank    saves  excavation  and  expenditure  on 

foundations  in  many  cases. 

Steel  tanks  should  be  well  grouted  in,  in  many  places,  when 
lowered  on  to  their  bed. 

Steel  tanks  require  more  maintenance  than  stone  or  brick  ones, 
and  more  steam  for  preventing  freezing  of  the  water  during  frosty 
weather. 

Cost  of  a  steel  tank  usually  one-half  to  two-thirds  that  of  an 
excavated  brick  or  concrete  one. 

Cost  of  steel  tanks  about  3'3d.  to  3'7d.  per  cubic  foot  capacity. 

Cost  of  brickwork  tanks  about  4'4d.  to  5'9d.  per  cubic  foot  capacity. 

The  plates  in  the  bottom  row  of  a  50  feet  deep  X  190  feet 
diameter  tank  have  been  made  If  inch  thick  X  4  feet  4  inches 
wide  X  24  feet  9  inches  long. 

It  is  usual  to  put  the  flanges  of  cast  iron  tank  bottom  plates  inside 
and  the  flanges  of  the  side  plates  outside. 

Tanks  may  with  advantage  be  left  large  enough  to  allow  of  an 
extra  lift  when  being  first  designed  and  laid  out,  although  it  may 
not  be  at  the  moment  required. 

The  larger  the  volume  of  water  in  a  tank  the  less  the  liability  to 
freeze. 

Thickness  of  Tank  Walls  at  any  point  in  inches  = 

Pressure  of  water  (pounds  per  square  inch)  X  radius  of  tank  in  inches 
Cohesive  force  of  wall  in  pounds  per  square  inch  -  pressure  of  water. 

Force  of  water  tending  to  burst  a  tank  outwards  =  62'5  x 
diameter  of  tank  x  £  (depth). 

Pressure  on  wall  of  tank  due  to  earth  backing  therefore  equals 
resistance  of  earth  X  outside  diameter  of  tank  X  £  (depth2). 

Resistance  of  the  weight  of  wall  equals  half  the  cubic  contents  of 
the  wall  in  feet  X  weight  of  1  cubic  foot  of  the  wall. 

Resistance  of  the  cohesion  of  the  material  of  the  wall  equals 
cohesive  force  X  height2  x  average  thickness  of  wall. 

Cohesive  force  of  bricks  in  cement  1  (cement  to  3  sand)  equal 
to  31,680  Ibs.  per  square  foot. 

Resistance  of  earth  backing  dry  equal  to  \  an  equal  column  of 
water.  (Sir  B.  Baker.) 

Resistance  of  earth  backing,  water-logged,  equal  to  1^  an  equal 
column  of  water.  (Sir  B.  Baker.) 

Resistance  of  earth  backing,  clay  or  earth,  equal  to  1,200  Ibs.  per 
square  foot.  (Newbigging.) 


204 


GAS  ENGINEER'S  POCKET-BOOK. 


Ultimate  Resistance  of  Loam  Earth  per  Square  Foot  in  Ibs. — 
E.  A.  Tests. 


Mean  Depth  of 
Anchorage  below 

Inclination  of  Force  drawing  the  Anchorage  (in  a 
Direction  perpendicular  to  its  Face). 

Surface. 

Vertical. 

1 

i 

* 

i 

1  foot 

808 

933 

1,244 

1,300 

1,430 

1  foot  6  inches      .     . 

1,040 

1,458 

2.100 

2,180 

2,360 

2  feet 

1,925 

2,700 

3,880 

4,032 

4,370 

3  feet   .... 

3,024 

4,400 

5.860 

6,160 

6,750 

4  feet 

5,470 

8,000 

10,660 

11,200 

12,260 

5  feet   .... 

14,112 

22,000 

29.330 

30,800 

33,730 

In  damp  sand  the  resistance  would  be  half  that  in  earth. 
A  factor  of  safety  in  tank  walls  of  3  is  ample. 

Resistance  of  Different  Earths  to  Horizontal  Compression.   (M.  Arson.) 

Sand 2.050  Ibs.  per  square  foot. 

White  tufa  (a  light  stony  powder)  1,640    .,      .,         „        „ 
Vegetable  earth  mixed  with  gravel     900    „      „         „        „ 

The  earths  were  well  watered  and  punned. 

The  Backing  to  Gasholder  Tank  Walls  should  be  well  punned  and 
watered  to  cause  it  to  have  direct  pressure  upon  the  wall,  as  cracks 
are  almost  invariably  found  in  a  vertical  direction  and  only  open  a 
very  slight  distance,  which  would  suggest  that  the  walls  have  then 
taken  up  the  support  of  the  backing. 

Clay  has  often  been  known  to  sustain  a  pressure  of  water  of 
15  Ibs.  per  square  inch,  or  about  1  ton  per  square  foot. 

One  cubic  yard* puddle  weighs  about  2  tons. 

Puddle  may  be  thrown  from  a  height  of  20  feet  with  advantage, 
but  should  not  be  laid  in  layers  of  more  than  10  inches  at  a  tine. 

Where  clay  is  to  be  found  upon  the  site  it  will  probably  be  cheaper 
to  construct  a  puddle  tank  than  a  rendered  one. 

Fuddle. — Work  the  clay  well  up  with  water  to  break  up  the 
original  formation,  and  bring  about  a  new  arrangement  of  the 
particles,  adding  sufficient  water  to  fill  up  every  pore. 

If  possible,  expose  the  clay  before  tempering  for  a  considerable 
time  to  the  air.  It  should  be  opaque,  not  crystallised,  with  a  dull 
earthy  fracture,  and  exhale  an  argillaceous  smell. 

Tenacity  and  power  to  retain  water  is  the  principal  requirement. 
If  a  roll  well  worked  up  by  hand  to  eight  or  ten  times  its  thickness 
be  suspended,  while  wet,  by  one  end  it  should  not  break.  It  should 
retain  its  original  quantity  of  water  when  formed  into  a  basin  and 
filled  for  24  hours,  if  covered  up  to  prevent  evaporation.  (W.  Gallon.) 

Puddle  should  be  put  in  in  layers  of  not  more  than  one  foot,  and 
should  be  thrown  in  with  force  to  cause  it  to  adhere  to  that  already 
in.  The  top  of  the  puddle  should  be  carefully  covered  when  any  dirt 
is  being  put  in  to  form  a  backing,  as  any  grit  in  the  puddle  may  cause 
a  leak,  owing  to  the  grit  preventing  a  thorough  adherence  of  the  two 
layers  of  puddle. 


TANK  WALLS.  205 

Puddle  should  be  laid  over  the  whole  of  the  surface  of  the  dumpling 
and  connected  all  round  to  that  under  and  on  the  outside  of  the  wall 
without  any  break. 

Brick  tanks  with  f  inch  cement  (neat),  in  two  coats,  can  be  made 
without  puddle,  and  will  prove  quite  tight. 

Should  a  leak  show  itself  when  the  pumping  has  stopped  for  testing 
the  soundness  of  the  tanks  stock-ramming  may  be  employed  to  fill 
up  the  space  where  the  leak  occurs.  In  doing  this  a  hole  is  first  cut  in 
the  wall  or  floor  of  the  tank  and  a  pipe  inserted  down  to  the  puddle 
level,  and  then  cartridges  of  clay  are  put  in  the  pipe  and  forced  down 
with  rammers.  These  latter  are  frequently  made  with  the  heads  so 
that  several  men  can  use  their  strength  to  ram  the  clay  well  into 
the  hole. 

In  puddled  tanks  the  pressure  of  the  water  is  thrown  upon  the 
puddle  and  earth  backing,  and  not  upon  the  wall  itself,  while  with  a 
cement-rendered  tank  the  pressure  is  upon  the  wall. 

Hoop  iron  or  thicker  wrought  iron  bands  are  often  imbedded  in 
the  cement  of  a  tank  wall,  and  considerably  add  to  the  strength.  They 
should  be  bent  round  and  turned  back  at  the  ends,  and  laid  so  that 
they  hook  one  into  the  other  and  form  a  continuous  band. 

Where  no  backing  is  used  to  help  Tank  Sides  to  resist  the  pressure 
of  Water  the  thickness  of  the  Cylinder  may  be  calculated  as  follows  :— 

When  the  thickness  is  less  than  g^th  the  radius  the  thickness  = 
Pressure  in  Ibs  per  square  inch 

—  -  —  ;  -  -r-.  —  —  -  :  —  -  X  radius  m  inches. 
Safe  strength  in  Ibs.  per  square  inch 

This  regards  the  material  as  only  subjected  to  tensile  strain. 
To  find  the  Thickness  at  base  of  Wall  to  resist  the  overturning  with 
the  pressure  of  quiet  water  level  with  its  top  and  no  backing  (wall 
with  vertical  back  and  sloping  face)  :•  — 
Thickness  of  base  at  foot  = 

(Hf  2  ft.  x  factor  of  safety*)  +  (batter  ^Tt.  x  sp.  gr.  of  wall) 
3  X  sp.  gr.  of  wall. 

Eequired  moment  of  stability  of  wall 
*Factor  of  safety  =       V>  ±    *      ±  - 

Overturning  moment  of  water. 

Where  cylindrical  hoops  are  placed  around  tanks,  to  find  the 
distance  apart  at  which  they  should  be  fixed  to  each  to  sustain  the 
same  strain  — 

Fix  upon  the  number  of  straps  required  then  for  the  first, 
fjl  X  total  No.  of  straps  X  depth  of  tank 

Total  No.  of  straps 

=  Distance  from  top  of  tank  for  1st  strap. 
For  the  second  strap,  ^/2  x  total  No.  of  straps  X  depth  of  tank 

Total  No.  of  straps. 
=  Distance  from  top  of  tank  for  2nd  strap. 

And  so  on  for  each  strap,  substituting  for  the  1  and  2  in  above 
formulas  the  number  of  the  strap  from  the  top. 


/( 


206 


GAS  ENGINEER'S  POCKET-BOOK. 


To  find  the  Pressure  of  Water  against  a  Tank  Side. 

Multiply  the  vertical  depth  in  feet  of  its  centre  of  gravity  below 
the  surface  of  the  water  X  the  area  of  surface  pressed  in  square  feet 
X  62'5  =  pressure  in  Ibs. 

The  pressure  of  liquids  being  always  perpendicular  to  the  surface 
at  any  point,  if  the  wall  be  vertical  the  pressure  is  horizontal. 

The  centre  of  pressure  is  always  one  third  of  the  vertical  depth 
from  the  bottom. 

Table  showing  the  Pressure  in  Ibs.  per  Square  Foot,  and  Pressure 
against  a  Plane  1  Foot  Wide  from  Top  to  those  Depths. 


Depth 
in 
Feet. 

Pressure 
per 
Square  Foot. 

Pressure 
on 
Plane. 

Depth 
in 
Feet. 

Pressure 
per 

Square  Foot. 

Pressure 
on 
Plane. 

1 

62 

31 

26 

1,625 

21,125 

2 

125 

125 

27 

1,687 

22,781 

3 

187 

281 

28 

1,750 

24,500 

4 

250 

500 

29 

1,812 

26,281 

5 

312 

781 

30 

1,875 

28,125 

6 

375 

1,125 

31 

1,937 

30,031 

7 

437 

1,531 

32 

2,000 

32,000 

8 

500 

2,000 

33 

2,062 

34,031 

9 

562 

2,531 

34 

2,125 

36,125 

10 

625 

3,125 

35 

2,187 

38.281 

11 

687 

3,781 

36 

2,250 

40^00 

12 

750 

4,500 

37 

2,312 

42,781 

13 

812 

5,281 

38 

2,375 

45,125 

14 

875 

6,125 

39 

2,437 

47,531 

15 

937 

7,031 

40 

2,500 

50,000 

16 

,000 

8,000 

41 

2,562 

52,531 

17 

,062 

9,031 

42 

2,625 

55,125 

18 

,125 

10,125 

43 

2,687 

57,781 

19 

,187 

11,281 

44 

2,750 

60,500 

20 

,250 

12,500 

45 

2,812 

63,281 

21 

,312 

13,781 

46 

2,875 

66,125 

22 

,375 

15,125 

47 

2.937 

69,031 

23 

,437 

16,531 

48 

3,000 

72,000 

24 

,500 

18,000 

49 

3,062 

75,031 

25 

1,562 

19,531 

50 

3,125 

78,125 

When  water  is  pressing  on  each  side  of  a  wall  at  different  levels 
the  pressure  at  any  point  can  be  found  by  setting  off  at,  say,  each  foot 
depth  the  pressure  on  the  wall  due  to  the  one  height  of  water  and 
upon  the  other  side  the  pressure  due  to  the  other  height.  Deducting 
the  lesser  pressure  from  the  greater  gives  the  pressure  upon  the  wall. 

Example. — A  wall  10  feet  long  has  water  to  its  full  height,  5  feet 
on  one  side  and  3  feet  high  on  the  other  ;  the  pressures  are  as  shown 
in  fig.  on  next  page.  The  excess  of  pressure  on  the  high  water  side  is 
always  equal  to  the  pressure  on  that  portion  9f  it  at  the  low  water  level. 


TANK   WALLS. 


207 


In  calculating  the  strength  of  Tank  Walls  the  tank  may  be  supposed 
to  break  in  two  halves  upon  the  axis  of  the  cylinder  ;  the  force  tending 
to  open  the  two  halves  is  the  pressure  of  the  water,  and  the  opposing 
forces  are  the  backing,  the  cohesive  nature  of  the  material  in  the 
wall,  arid  the  weight  of  the  masonry. 

The  overturning  moment  of  the  water  in  Ibs.  =  62'5  X  diameter  of 

tank  X  dePth  of  tank3 

6 
The  moment  of  resistance  of  the  earth  backing  =  constant    X 

depth  of  tank2 
external  diameter  of  wall  X 

Moment  of  resistance  of  the  weight  of  the  masonry  = 
112  X  thickness  of  walls2  X  external  diameter  of  walls  x  depth  of  tank 

2 

Moment  of  resistance  due  to  cohesion  =  30,700  X  depth  of  tank2  X 
thickness  of  walls.  Dimensions  all  in  feet. 

Pressure  due  to  Head  of  Water  may  compress  the  earth  left  in  to 
form  dumpling  in  tank  and  cause  leakage.  See  resistance  of  earths 
to  pressures,  page  204. 

Iron  bands  are  inserted  in  the  concrete  at  East  Greenwich  tank  of 
5  inches  X  ^  inc^  na^  iron,  riveted  to  form  complete  rings,  and 
placed  2  feet  apart  vertically. 

A  Water-tight  Concrete  can  be  made  when  two  volumes  of  sand  are 
added  to  one  of  Portland  cement,  ground  fine  enough  to  allow  nine- 
tenths  to  pass  through  a  sieve  with  14,400  meshes  in  each  square 
inch.  A  coarser  cement  passing  only  three-fourths  through  the  same 
sieve  will  not  make  a  water- tight  concrete  when  mixed  with  only  one 
and  a  half  times  its  volume  of  sand. 


208 


GAS  ENGINEER'S  POCKET-BOOK. 


Thickness  of  Sheets  of  Wrought  Iron  for  Tanks  of  Different 
Diameters  and  Depths. 

Factor  of  safety,  |th.     Deduction  for  rivet  holes,  40  per  cent. 


20  30  40 

Depth  in  feet. 


CONCRETE   TANK   WALLS.  209 

When  the  first  batch  of  concrete  is  mixed,  the  quantity  of  water 
per  bushel  of  dry  materials  should  be  noted,  and  the  same  propor- 
tions held  to  with  the  other  batches,  uniformity  in  this  respect  being 
of  the  utmost  importance.  As  much  water  should  be  added  as  will 
give  a  mixture  that  allows  a  man  treading  over  it  to  sink  in  to  a 
depth  of  at  least  6  inches.  No  stones  used  for  concrete  should  be 
larger  than  will  pass  through  a  mesh  2  inches  square.  Concrete 
should  not  be  dropped  or  made  to  slide  down  a  shoot,  and  inferen- 
tially  it  should  be  laid  with  a  spade  without  a  fall  of  any  kind,  and 
then  it  requires  to  be  trodden  down. 

Stout  bars  of  flat  iron  laid  into  the  walls  of  a  concrete  tank,  and 
hooked  together  to  form  a  complete  ring  on  edge  are  said  to  give 
great  strength  to  the  same.  The  expansion  of  iron  and  cement  con- 
crete being  nearly  equal  prevents  fracture  between  the  two  materials. 

Firebrick  rubbish  and  furnace  clinkers  form  with  sand  or  sharp 
grit  excellent  material  for  concrete. 

Concrete  composed  of  1  part  cement  to  10  or  12  coke  breeze  is 
porous. 

A  good  coat  of  asphalt  will  render  a  tank  quite  water-tight. 

A  coating  of  hot  asphalt  and  tar  is  also  used  to  render  cement 
tanks  water-tight. 

Rendering  is  usually  done  with  equal  parts  Portland  cement  and 
sand,  arid  laid  on  from  £  inch  to  f  inch  thick,  with  a  final  layer  of 
neat  cement  carefully  trowelled  on  about  £  inch  thick. 

French  engineers  usually  specify  a  much  greater  thickness  of 
cement  and  sand  in  equal  parts,  without  the  neat  cement  layer. 

Portland  cement  rendering  usually  made  of  1  cement  to  3  of 
well  washed  sand. 

External  mouldings  and  linings  to  water  tanks  neat  cement. 

A  simple  Rule  to  avoid  loss  in  Cupping  is,  when  constructing,  to 
make  the  tank  measured  from  the  rest-stones  the  full  depth  of  the 
various  lifts,  plus  a  depth  equal  to  the  difference  between  the  dis- 
placement of  the  inner  and  outer  lifts,  and  add  a  margin  of  3 
inches. 

Pumps  for  gasholders  should  be  made  with  an  outer  casing  to  the 
bottom  of  the  pipes  to  be  pumped,  so  that  the  pump  may  be  removed 
for  repairs  without  an  escape  of  gas. 

Tank,  114  feet  x  31  feet  deep,  at  Wellingborough,  made  with 
Portland  cement  concrete  7  to  1,  and  puddled  at  back,  no  rendering, 
concrete  over  dumpling  (of  clay)  6  inches  thick. 

Wall  of  tank  123  feet  diameter  x  30  feet  deep  =  3  feet  6  inches 
thick  at  bottom  to  2  feet  thick  at  top. 

A  cast  iron  tank  112  feet  diameter  X  25  feet  deep  has  been  erected, 
weighing  about  500  tons. 

Concrete  made  with  clinkers  ana  broken  firebricks  and  retorts  said 
to  be  stronger  in  tension  than  if  made  all  Thames  ballast. 
thickness  of  Sheets  of  Brought  Iron  for  Tanks. 

=  Pressureinf.Ibs-Pe7quareinch  x  radius  in  inches 
sate  strength 

See  diagram  opposite. 

G.E.  P 


210  GAS  ENGINEER'S  POCKET-BOOK. 


GASHOLDERS. 

General  Notes. 

Mr.  G-.  Livesey  stated  (1882)  that  201.  per  1,000  cubic  foot  capacity 
was  a  usual  cost  of  gasholders  of  moderate  size. 

Two  holders  of  about  equal  size  should  be  provided  in  all  works. 

When  extending,  holder  capacity  should  be  doubled  by  the 
addition  of  one  holder  of  equal  capacity  to  all  the  previous  ones 
combined. 

Single  lift  holders  should  not  be  usea  except  for  less  than  10,000 
cubic  feet  capacity. 


Height  of  lift  should  = 

Holders  above  500,000  cubic  feet  capacity  should  be  three  lifts. 

When  weight  is  required  to  give  necessary  pressure  increase  the 
thickness  of  sheets  and  cups. 

No  necessity  to  break  joint  in  side  sheets,  as  load  is  much  below 
the  strength  of  the  sheets. 

It  should  be  borne  in  mind  that  'the  larger  the  sheets  the  less  rivets 
are  required,  and  the  liability  to  leakage  is  reduced. 

The  strain  on  top  sheets  diminishes  in  exact  proportion  to  the  rise, 
and  is  uniform  throughout  the  top  sheets. 

Usual  rise  =  —  20  —  •    Shape«of  dome  equals  segment  of  a  sphere. 

With  rise  =  diameter,  No.  11  Birmingham  wire  gauge  sheets  are 
20 

sufficient  up  to,  say,  175  feet  diameter,  but  when  larger,  No.  10  sheets 
and  an  increased  rise  would  be  better.  Rivets  ^  inches  diameter. 

The  crown  curb  in  trussed  holders  has  not  much  work  to  do. 

The  best  form  of  curb  is  an  angle  iron  or  steel,  but  in  larger  holders 
where  the  compressing  strain  may  equal  200  tons  other  pattern  curbs 
must  be  adopted. 

Mr.  Livesey  considers  40  Ibs.  per  foot  as  the  maximum  wind  force 
likely  to  be  exerted  on  a  gasholder  ;  and  57  per  cent,  of  this  force  is 
exerted  on  the  cylinder  as  compared  with  a  flat  surface. 

When  diagonal  bracing  of  sufficient  strength  is  in  use,  the  side 
strength  of  the  columns  or  posts  need  not  be  great  as  the  strain  is 
resisted  by  the  bracing. 

For  moderate  sized  gasholders.  Mr.  G.  Livesey  and  Mr.  C.  Hunt 
prefer  cast  iron  columns. 

Theoretically  if  pressure  is  brought  upon  a  cylinder  it  tends  to 
expand  it  in  all  directions. 

In  a  gasholder  at  New  Jersey,  U.S.A.,  which  overturned  in  a  gale, 
all  the  columns  but  one  fell  outwards. 

Mr.  Foulis  considers  50  Ibs.  per  square  foot  should  be  allowed  for 
as  wind  pressure  on  gasholders. 

Mr.  Cripps  suggests  gussets  to  connect  the  first  row  of  top  sheets 
with  the  top  row  of  side  sheets  in  small  holders. 


NOTES   ON   GASHOLDERS.  211 

To  find  the  strain  on  top  sheets — 

18-3  Weight  of  side  sheets  in  tons  =  gtrain 
angle  of  top  in  degrees 


(Half  diameter  of  holder2  +  rise2)  X  effective  pressure  of 

gas  X  diameter  of  holder  in  feet g      .  ^ 

8  X  rise 

It  is  essential  that  gasholders  should  be  maintained  perfectly  level. 

The  Old  Kent  Road  type  of  gasholder  "is  one  of  that  class  of 
structures  in  which  it  is  impossible  to  foresee  the  exact  intensity  and 
nature  of  the  stresses."  (Sir  B.  Baker.) 

Steel  curbs  are  better  than  iron  as  they  stand  a  higher  compressive 
strain. 

Two  angles,  one  set  at  each  end  of  the  first  and  thicker  row  of  top 
sheets,  is  the  easiest  and  simplest  method  of  constructing  a  curb  where 
considerable  strain  has  to  be  resisted,  as  each  inch  of  section  is 
profitably  utilised. 

Radial  rollers  spread  the  wind  pressure  on  one  quarter  of  the 
guides. 

Tangential  rollers  spread  the  wind  pressure  on  one  half  of  the 
guides. 

The  two  combined  spread  the  wind  pressure  on  three  quarters  of 
the  guides. 

Mr.  Webber  considers  the  two  combined  spread  the  wind  pressure 
on  two-thirds  of  the  guides. 

With  tangential,  or  these  combined  with  radial  rollers,  the  pressure 
from  the  curb  is  better  distributed,  and  the  strain  upon  the  guides 
is  thrown  in  a  tangential  direction,  thereby  bringing  the  diagonal 
bracing  directly  into  use  in  the  position  it  is  best  able  to  resist  the 
strain. 

Stays  to  inner  lifts  of  gasholders  are  usually  made  of  T  iron  trussed, 
but  in  large  holders  channel  and  H  iron  frequently  take  the  place 
of  the  T. 

Channel  iron  forms,  on  the  outer  lifts,  both  a  stay  and  also  a  guide 
path  for  the  next  inner  lift  roller. 

Vertical  stiffeners  require  securely  fastening  to  cups  and  grips. 

Vertical  rows  of  thicker  section*  plate  are  not  advisable,  as  the 
riveting  to  the  next  rows  on  either  side  is  not  so  tight. 

Sometimes  the  stiffeners  are  riveted  to  the  side  sheets  by  rivets 
at  very  close  pitch,  sometimes  at  1  foot  apart,  and  at  others  only 
attached  to  cup  and  grip. 

Gasholder  sheets  should  never  be  allowed  to  oxidise,  but  receive  a 
coat  of  boiled  oil  immediately  they  are  planished  and  punched. 

An  average  gasholder  contains  more  than  40  feet  run  of  riveting 
and  joint  per  100  cubic  feet. 

It  is  not  considered  advisable  to  rivet  crown  sheets  to  trussing  in 
holders,  as  it  prevents  the  sheeting  ballooning  out  into  a  spherical 
shape,  and  throws  great  strain  on  the  rivets.  (Cripps. ) 

P2 


212 


GAS  ENGINEER'S  POCKET-BOOK. 


Weight  of  bell  of  holder  is  almost  equal  to  that  of  the  guide 
framing  in  wrought  iron  or  steel. 

All  rivets  should  be  well  brought  up  with  the  set,  firmly  held  and 
properly  riveted,  if  a  sound  job  is  to  be  secured. 

All  holders  should  be  well  painted  every  year. 

Wyatt  says  about  20  Ibs.  weight  of  wrought  iron  is  used  per 
superficial  foot  of  sheeting  (inclusive  of  the  guide  framing).  Of  this 
12  Ibs.  is  the  holder  proper  and  8  Ibs.  the  framing.  (October,  1887.) 

Side  sheets  vary  in  thickness  from  No.  11  in  large  holders  to 
17  Birmingham  wire  gauge  in  small  ones. 

The  depth  of  each  lift  must  never  be  less  than  ith  of  the  diameter 
of  the  holder  ;  and  it  will  work  better  if  it  be  Jth  or  |th  the  diameter. 

With  holders  up  to  120  feet  diameter,  it  is  cheaper  to  put  in  a 
light  trussing  than  to  place  a  wooden  framing  in  the  tank  ;  but  above 
this  size  it  is  more  economical  to  put  a  timber  framing  to  receive  the 
holder  when  down.  The  trussing  of  a  gasholder  should  never  be 
more  than  10  to  12  per  cent,  of  the  floating  weight.  (Cripps.) 

Useless  weight  due  to  trussing  of  holders  may  cause  an  increase  ot 
10  to  12  per  cent,  in  the  fuel  account  of  the  boiler  supplying  steam 
to  the  exhauster  engine. 

Large  single  lift  gasholders  are  often  made  so  light  that  weights 
are  required  to  cause  them  to  throw  sufficient  pressure.  In  this  case 
water  troughs  should  be  employed  so  that  the  water  can  be  run  in  at 
night  when  pressure  is  required,  and  the  back  pressure  in  works 
relieved  during  the  day  in  running  off  the  water. 

Mr.  C.  Hunt  prefers  cast  iron  columns  for  holders  of  moderate  size, 
as  a  cast  iron  column  is  cheap  and  easy  to  construct. 

It  has  been  proposed  to  carry  the  pipe  from  the  meter  to  the 
governor  house,  and  there  connect  it  by  a  valve  to  the  town  mains 
before  leading  it  to  the  gasholders,  so  that  in  case  of  a  stoppage  at 
the  gasholders  it  can  be  at  once  turned  on  direct  into  the  town,  a 
governor  being  used  to  give  warning  of  the  necessity  of  turning  on 
the  valve. 


Bivets  Bequired  to  Join  Different  Thickness  Plates  in  Gasholder 
Construction.     (C.  and  W.  Walker.) 

|  inch     to  |  inch  require  $  inch  rivets  at  2£  inches  pitch. 

"      "  2|     ,"         " 

»       M  2        „ 

,-       „  4      „ 

..       .,  1    inch        ,, 

,,  If  inches     .. 

;;  ;,  11  » 


1  » 

1      » 

1      n 

f      " 

i     » 

f      ?? 

i     ,. 

10  B.W.G. 

10  B.W.G. 

10  B.W.G. 

10  B.W.G. 

^  inch 

tinch 

ra     » 

n 

f      » 

Riveting  (single)  to  No.  11  plates 
„       (double)          „ 


=  3Uh  weight  of  plates. 
=  Ath 


(single)  |  inch  plates  1£  inch  pitch  = 
(double)     „        „  „          „      = 


STRAINS   ON   CROWNS. 


213 


Biveting  to  irons  2£  inches  to  6  inches  pitch  average  $th'of  weight 
of  plates. 

Not  possible  to  join  a  thin  plate  to  a  thick  one  and  make  a  gas- 
tight  joint,  therefore  the  second  plate  from  curb  should  be  half  way 
between  outer  plate  and  crown  sheeting  in  thickness. 

Reduce  the  thickness  of  sheets  gradually  to  ensure  tightness. 

Always  rivet  a  thin  sheet  to  a  thick  one,  not  the  thick  to  the  thin. 
Allowance  for  lap  of  plates — 

When  the  lap  equals  1£  inches  add  ^  inch  or  7  per  cent,  (no  rivets). 

Allowance  for  waste  on  rivets,  10  per  cent. 

„        for  rivets,  bolts,  and  laps  over  and  above  plates  £  to  $. 

Expansion  of  cast  iron  100  feet  long  =  f  inch  for  100°  F.  (Horton.) 
„          wrought  iron  „     „       „     =^    „      „  100°  F. 
copper        '    „     „      „    =1-28,,     „  100°  F. 

Iron  expands  with  tension  and  contracts  with  compression  i^th 
Of  its  length  per  ton  per  square  inch.  (Cripps.) 


Table  showing  the  Strains  on  a  Holder  200  feet  diameter,  with 
Different  Rises  of  Crown,     (V.  Wyatt.) 


Rise  of 
Crown  of 
Holder  in 
Feet. 

Surface  of 
Domeequals 
6-2832  R.  V. 
SquareFeet. 

Ratios  of 
Dome  to 
Plane  Sur- 
face Area. 

Radius  of 
Dome. 

Tension 
on  £  of 
Dome. 

Tension  on 
1  Foot  in 
Length  of 
Dome. 

Compres- 
sion on 
One  Sec- 
tion of 
Top  Curb. 

0 

31416 

I'OOOO 

0 

10 

31730 

1-0100 

505 

528* 

3-40 

331 

15 

32091 

1-0214 

340 

348 

2-20 

213 

20 

32672 

1-0400 

260 

272 

1-80 

161 

25 

33300 

1-0600 

212 

222 

1-40 

126 

40 

36442 

1-1600 

145 

151 

0-96 

70 

50 

39250 

1-2500 

125 

131 

0-83 

51 

100 

62832 

2-0000 

100 

104£ 

0-67 

00 

Doubling  the  rise  of  the  crown  reduces  the  strain  on  the  top 
sheeting  one  half  ;  here  it  is  well  to  break  joints  as  strength  is  required, 
and  96  per  cent  of  the  plates  can  be  ordinary  square  sheets.  Strain 
being  equal  on  all  crown  sheets,  they  should  be  of  equal  thickness. 

diameter 
Radiating  strips  are  unnecessary.      Usual  rise  of  crown  = 

in  the  form  of  a  segment  of  a  sphere,  in  this  case  No.  11  gauge  sheets 
are  sufficient  for  gasholders  of  moderate  size,  but  for  200  feet  diameter 
holders  No.  10  gauge  sheets  better  and  larger  rise.  Rivets  in  crown 
sheets  should  be  ^  inch  diameter. 

Trussed  holders  require  only  moderate  curbs. 

Cheapest  (and  easiest  and  simplest  to  construct)  curb,  is  two  angles 
of  iron  or  steel,  one  at  each  end  of  a  flat  plate. 


214  GAS  ENGINEER'S  POCKET-BOOK. 

Messrs.  C.  and  W.  Walker  construct  all  their  holders  to  one  curve  for 
ithe  top,  which  is  an  arc  of  a  circle  405  feet  radius,  but  for  holders 
under  50  feet  diameter  give  them  a  greater  rise  than  this. 

Strain  on  crown  sheeting  varies  almost  inversely  as  the  rise. 

Rise  of  crown  sometimes  made  '875  of  an  inch  per  foot  in 
diameter,  which  is  the  form  it  would  take  with  a  bursting  pressure. 

It  has  been  suggested  that  a  radius  of  400  feet  for  gasholder  crowns 
should  be  used,  as  £  inch  sheets  are  then  strained  to  what  they  will 
safely  bear  in  most  gasholders. 

Pressure  of  snow  may  cause  a  load  of  5  Ibs.  per  square  foot  over 
£th  the  area  of  a  holder,  and  the  centre  of  gravity  may  be  (say) 
£th  diameter  from  edge.  (F.  S.  Cripps.) 

1  cubic  foot  fresh  snow  5  to  12  Ibs.  .        .        Trautwine. 

1       „      „     snow  compacted  by  rain  15  to  50  Ibs.         „ 

Weight  of  gasholder  bell  equals  weight  of  1  cubic  foot  water  X  area 
on  water  line  in  feet  X  pressure  thrown  in  feet,  or, 

Area  X  5-2083  =  Ibs.  per  inch  pressure.    (F.  S.  Cripps.) 


Equilibration  chains  to  gasholders. 
Formula  for  required  weight  of  chains  : 

w  =  weight  of  1  foot  vertical  of  gasholder  in  Ibs. 
G  =  specific  gravity  of  iron  in        ditto. 
W  =  weight  of  1  foot  of  chain  in  Ibs. 
N  =  number  of  chains. 


To  find  the  weight  of  a  gasholder  — 


W  =  weight  in  Ibs. 
A  =  area  of  water  surface  in  sq.  ft. 
p  =  pressure  in  inches  thrown. 
then,  W  =  A 


To  find  pressure  of  a  gasholder  :  — 

W  =  weight  in  tons. 
d  =  diameter  in  feet. 
p  =  pressure  in  inches. 

547  W 


FORCE    OF    THE    WIND. 


215 


Force  of  the  Wind. 


Velocity. 

Force. 

Miles  per 
Hour. 

Feet  per  „ 
Second. 

Lbs.  per 
Square  Foot. 

1 

1-47 

•005 

Hardly  perceptible. 

2 

2-93 

•012 

3 

4-40 

•044 

Just  perceptible. 

4 

5-87 

•048 

5 

7-33 

•123 

Gentle  pleasant  breeze. 

10-0 

•229 

10 

14-67 

•300 

Pleasant  brisk  gale. 

20-0 

•915 

15 

22-0 

1-107 

20 

29-34 

1-968 

30-0 

2-059 

25 

36-67 

3-075 

Very  brisk  gale. 

40-0 

3-660 

30 

44-01 

4-429 

50-0 

5-718 

35 

51-34 

6-027 

High  winds. 

40 

58-68 

7-873 

60-0 

8-234 

Hard  gale. 

70-0 

11-207 

50 

73-35 

12-300 

Very  high  winds. 

80-0 

14-638 

60 

88-12 

17-715 

A  storm. 

90-0 

18-526 

100-0 

110-0 

22-872 
27-675 

A  great  storm. 

80 

117-36 

31-490 

A  hurricane. 

120-0 

32-926 

130-0 

38-654 

90 

132-02 

39-852 

140-0 

44-830 

100 

146-7 

49-200 

150-0 

51-462 

120 

176-04 

70-860 

216 


GAS  ENGINEER'S  POCKET-BOOK. 


Velocity  and  Pressure  of  Wind.    (Another  Rule.) 


Miles 
Hour. 

Feet  per 
Second. 

Lbs.  pei- 
Square 
Fcot. 

Miles 
per 
tlour. 

Feet  per 
Second. 

Lbs.  per 
Square 
Foot. 

Miles 
per 
Hour. 

Feet  per 
Second. 

Lbs.  per 
Square 
Foot. 

1 

1-46 

0-005 

18 

26-40 

1-620 

35 

51-33 

6-125 

2 

2-93 

0-020 

19 

27-86 

1-805 

36 

52-80 

6-480 

S 

4-40 

0-045 

20 

29-33 

2-000 

37 

54-26 

6-845 

4 

5-86 

0-080 

21 

30-80 

2-205 

38 

55-73 

7-220 

5 

7-33 

0-125 

22 

32-26 

2-420 

39 

57-20 

7-605 

6 

8-80 

0-160 

23 

33-73 

2-645 

40 

58-66 

8-000 

7 

10-26 

0-245 

24 

35-20 

2-880 

41 

60-13 

8-405 

8 

11-73 

0-320 

25 

36-66 

3-125 

42 

61-60 

8-820 

9 

13-20 

0-405 

26 

38-13 

3-380 

43 

63-06 

9-245 

10 

14-66 

0-500 

27 

39-60 

3-645 

44 

64-53 

9-680 

11 

16-13 

0-605 

28 

41-06 

3-920 

45 

66-00 

10-125 

12 

17-60 

0-720 

29 

42-53 

4-205 

46 

67-46 

10-580 

13 

19-06 

0-845 

30 

44-00 

4-500 

47 

68-93 

11-045 

14 

20-53 

0-980 

31 

45-46 

4-805 

48 

70-40 

11-520 

15 

22-00 

1-125 

32 

46-93 

5-140 

49 

71-86 

12-005 

16 

23-46 

1-280 

33 

48-40 

5-445 

50 

73-33 

12-500 

17 

24-93 

1-445 

34 

49-86 

5-780 

60 

88-00 

18-000 

Formula  for  obtaining  the  Velocity  of  High  Winds  from  the 
Pressure. 

Velocity  =  V  10  X  pressure. 


Formula  for  obtaining  the  Pressure  of  High  Winds  from  the 
Velocity. 


A  maximum  wind  pressure  of  56  pounds  per  square  foot  is  recom- 
mended in  calculations  for  railway  bridges  and  viaducts. 

Greatest  pressure  of  wind  recorded  in  pounds  per  square  foot  at  :  — 


Aberdeen 

.     41 

Liverpool 

Armagh     . 

.     27 

London     . 

Birmingham  . 

.     27 

Valentia 

Edinburgh 

.     35 

Yarmouth 

Falmouth 

.     53-7 

Brussels 

Glasgow    . 

.     47 

Paris 

Greenwich 

.     42 

Bombay 

Halifax     . 

.     30-2 

Calcutta    . 

Holyhead 

.     64 

Madras  . 

Kew 

.     27 

90 

20-2 

65-6 

42-2 

22 

17 

38 

40 

34 


WIND    PRESSURES.  217 

Allowance  for  Wind  and  Snow. 

Weight  of  snow  on  horizontal  surface  =  say  15*5  Ibs.  per  square  foot. 
Wind  pressure  on  surface  at  right  )  9,.fi  1K 

angles  to  line  of  impact       '          I    ' 
Wind  pressure  on  surface  in  spe-  )  Q1.n  IK* 

cially  exposed  positions  I    ~    »    dl      'bs'   " 

(D.  K.  Clark.) 

According  to  returns'  from  the  Greenwich  Observatory  during  20 
years  the  greatest  pressure  equal  to  28  Ibs.  per  square  foot  from  the  west. 

Velocity  of  the  wind  (feet  per  second)  squared  x  -002283  =  Ibs. 
pressure  per  square  foot. 

At  the  Eiffel  Tower  it  was  found  that  the  wind  was  3  times  as 
strong  at  303  metres  from  the  ground  as  it  was  at  21  metres,  the 
velocity  at  the  higher  level  in  summer  exceeding  8  metres  per  second 
during  39  per  cent,  of  the  time  and  10  metres  per  second  during  21 
per  cent. 

Observations  at  the  Eiffel  Tower  show  an  increase  of  33  per  cent, 
in  velocity  and  pressure  of  wind  per  100  feet  in  height. 

Within  certain  limits  the  intensity  of  wind-pressure  increases  with 
the  area  of  the  receiving  surface  ;  but  over  large  areas  the  maximum 
is  not  reached  in  practice,  owing  to  the  wind  moving  in  concentrated 
gusts.  In  designing  structures,  although  56  Ibs.  per  square  foot  might 
be  looked  upon  as  the  standard,  this  should  be  modified  according  to 
the  circumstances  of  the  case,  viz.:  with  the  height  from  ground 
level,  the  unsupported  width,  and  the  angle  of  incidence.  Pressures, 
according  to  received  tables,  varied  from  16  Ibs.  at  ground  level,  to 
80  Ibs.  at  a  height  of  200  feet ;  and,  in  the  latter  case,  from  80  Ibs.  at 
a  width  of  10  feet  to  40  Ibs.  at  a  width  of  1,000  feet,  while  the 
multiplier  for  angle  varied  from  0'45  at  5  degrees  to  TOO  at  60  to  90 
degrees.  (Professor  Adams.) 

Sir  G.  Stokes  recommends  that  the  rate  of  travel  of  cup  anemometer 
should  be  multiplied  by  2-4  instead  of  3  to  get  the  velocity,  and  that 
velocity  2  x  0'0035  should  equal  pressure  instead  of  velocity  2  x  0'005. 

Maximum  wind  pressure  usually  allowed  =  O'Ol  v2  ;  ^  =  velocity 
of  wind  by  cup  anemometer. 

In  France  velocity  of  storms  is  taken  at  100  miles  per  hour,  and 
pressures  up  to  60  Ibs.  per  square  foot  over  the  effective  area  of  1 
truss  of  a  solid  truss  bridge,  or  T5  trusses  of  an  open  trussed  bridge. 

In  America  wind  pressures  of  30  Ibs.  per  square  foot  are  allowed  on 
large  surfaces  and  from  40  to  50  Ibs.  per  square  foot  on  small  surfaces. 

Velocity  of  high  winds  =  VlO  v 

<o  2 
Pressure  in  Ibs.  per  square  foot  =  — 

Greatest  wind  pressures  observed  at  the  Forth  Bridge  were  by  large 
fixed  gauge  27  ibs.,  by  small  fixed  gauge  41  Ibs.,  and  by  revolving 
gauge  35  Ibs.  per  square  foot. 

If  pressure  be  exerted  against  a  cylinder  it  tends  to  extend  the 
cylinder  radially  in  all  directions.  (C.  Hunt.) 


218 


GAS  ENGINEER'S  POCKET-BOOK. 


Gasholders  are  now  made  to  stand  a  maximum  crushing  strain 
equalling  a  pressure  of  20  Ibs.  on  the  square  foot,  exerted  on  a  plane 
represented  by  50  per  cent,  of  the  area  of  vertical  transverse  section 
of  the  holder.  (Newbigging,  August  28th,  1888.) 

Pressure  on  guide  columns  usually  taken  as  equal  to  the  total  wind 
pressure  divided  among  the  guide  columns  upon  which  the  rollers 
bear  at  one  time,  and  this  again  divided  among  the  different  rollers  to 
each  lift. 

With  the  upright  guide  form  of  standard  they  are  capable  of 
resisting  the  pressure  of  the  radial  rollers,  while  the  diagonals  resist 
the  lateral  strains. 

Johnson's  "  Theory  of  Framed  Structures  " — Wind  pressure  P  = 
0*004  v  2  ;  where  v  =  velocity  in  miles  per  hour. 

Mr.  Cripps  uses  a  wind  pressure  of  34  Ibs.  per  square  foot. 

Pressure  of  wind  on  a  gasholder  equals  16  Ibs.  per  square  foot  over 
the  entire  diametrical  section.  (F.  S.  Cripps.) 


Wind  Pressure  on  Circular  Objects. 

Let  do  =p,  force  of  wind  acting  parallel  to  the  diameter  b  a. 
Kesolve  this  into  its  component  parts  acting  at  right  angles  to  one 
another  at  the  point  c,  one  of  them,/c,  being  a  normal  to  the  curve  ; 
we  then  have/  e  as  representing  the  force  of  the  wind  acting  towards 


the  centre  of  the  circle,  and/ c  =.p  cos.  angle  d  c  f.  Resolving  this  force 
f  c  at  the  point  g,  so  as  to  measure  the  effective  force  exerted  in  the 
direction  g,  and  parallel  to  the  wind  we  have  the  effective  pressure 
P  =  j?  cos.'2'  angle  d  cf.  This  angle  d  cf  ranges  from  0°  to  90°,  and 


WIND   PRESSURES   ON    CURVED   SURFACES.  219 

taking  a  sufficient  number  of  angles  we  obtain  cos.2  angle  dcf= 
about  '5  ;  therefore  mean  effective  pressure  of  wind  against  semi-cir- 
cumference P  =  -op.  (Bancroft.) 

Greatest  wind  likely  to  press  upon  gasholder  equals  26  Ibs.  per 
square  foot  of  diametrical  section  of  the  bell. 

For  the  reduction  of  wind  pressure  on  a  circular  surface  to  an 
equivalent  plane  area  (such  as  an  arched  roof  or  a  gasholder) — 

Prof.  Rankine  gives  .         ...  0'5 

M.  Arson  „ 0'46 

R.  J.  Button        „  ....  0-67 

W.  H.  Y.  Webber  „ 0-5 

Molesworth           „  ....  0'75 

G.  Livesey  ., 0'57 

Prof.  Adams          „  ....  0'7854 

Walmisley  „ 0*56 

V.  Wyatt              „  ....  1-0  (October,  1887) 

Bancroft  „ 0'5 

Cripps                   „  .         .         .         .0-3 

Sir  B.  Baker         „ 0'41 

Newbigging         „  .                .        .  0*5  area  of  section. 

Trautwine  „ 0'5    „  „ 

Prof.  Kernot  (of  Melbourne  University) 

gives 0-5    „  „ 

Prof.  Kernot,  of  Melbourne  University,  found  pressure  on  one  side 
of  a  cube  =  0'9  that  on  a  thin  plate  of  the  same  area  ;  and  in  lattice 
work,  in  which  openings  =  50  per  cent,  total  area,  the  pressure  =  80 
per  cent,  of  that  upon  a  plate  =  the  total  area.  Pressure  on  octagonal 
prism  =  20  per  cent,  more  than  upon  circumscribing  cylinder. 

Pressure  on  sphere  =  0'36  of  a  thin  circular  plate  of  equal 
diameter.  Prof.  Kernot  also  recommended  20  Ibs.  per  square  foot  as 
a  maximum  upon  areas  of  not  less  than  300  square  feet,  and  30  Ibs. 
for  smaller  surfaces  in  position  of  full  exposure. 

To  find  approximate  area  of  a  segment  of  a  circle,  multiply  versed 
sine  by  -6  X  chord  =  area. 

Cost  of  six-lift  holder,  at  East  Greenwich,  of  12,000,000  cubic  feet 
capacity,  two  upper  lifts  to  go  outside ;  framing  designed  by 
F.  Livesey. 

Contract  amount,  £41,915. 

Wrought  iron  used 1,840  tons 

Cast  iron  , 60    „ 

Steel  320    , 


2,220    „ 

Cost  per  1,000  cubic  feet  £3  105.     Cost  of  tank  and  holder,  say  £5. 

Cost  of  gasholders  equals  cost  of  the  remaining  manufacturing 
plant.  (C.  Hunt.) 

Cost  of  gasholders  equals  one-third  of  the  remaining  manufacturing 
plant.  (G.  Livesey.) 


220  GAS  ENGINEER'S  POCKET-BOOK. 

Notes  on  Guide  Framing. 

Guide  framing  must  be  strong  enough  to  resist  all  strain  from 
snow  and  wind,  jamming  of  rollers,  and  guides  out  of  plumb. 

The  lighter  forms  of  guide  framing  depend  largely  upon  the 
strength  of  the  curb  and  grips  to  prevent  distortion,  but  it  is  better  to 
ignore  this  strength  when  calculating  the  guide  framing,  and  make 
the  latter  strong  enough  to  do  all  the  resisting  itself. 

If  the  diagonal  bracing  is  properly  placed  and  of  sufficient  strength 
the  greatest  portion  of  the  strain  may  be  resisted  by  it. 

Diagonal  bracing  with  the  old-fashioned  ring  for  tightening  in  the 
centre  is  weak,  coupling  screws  serving  the  purpose  much  better  with 
clips  where  the  braces  cross. 

Make  the  standard  strong  enough  to  transmit  the  strain  from  the 
front  to  the  outside  member. 

The  strain  upon  the  uprights  of  a  gasholder  framing  is  a  cantilever 
one. 

In  designing  gasholder  framing  use,  as  far  as  possible,  the  same 
size  and  section  of  iron,  to  avoid  the  expense  of  having  a  number  of 
different  pattern  bars  rolled.  (J.  Somerville.) 

Wrought  iron  in  gasholder  framing  has  been  objected  to  on  the 
score  of  rusting,  but  a  coat  of  paint  every  two  or  three  years  will  cure 
this. 

Gasholder  guides  should  be  fixed  leaning  inward  slightly,  according 
to  the  contraction  of  the  curb  when  fully  inflated. 

All  the  wrought  iron  in  gasholder  construction  should  withstand  a 
tensile  strain  of  21  tons  per  square  inch,  and  should  be  absolutely 
tested.  (J.  Somerville.) 

By  tangential  rollers  the  strain  is  thrown  mainly  upon  the  tension 
rods  and  cross  girders  of  the  framing. 

Make  as  many  triangles  in  the  guide  framing  as  possible  in  pre- 
ference to  parallelograms. 

The  yielding  of  wrought  iron  or  steel  framing  to  gasholders  is  said 
to  be  of  advantage,  cast  iron  columns  and  girders  having  often  broken 
through  undiscovered  flaws,  and  caused  wrecking  of  the  whole 
structure. 

"  The  steadiness  of  a  holder  depends  far  more  upon  the  tightness  of 
the  bottom  rollers  than  upon  any  other  condition.  It  is  the  practice 
of  good  gasholder  erectors  to  make  the  bottom  rollers  fit  the  tank 
guides  as  tightly  as  they  can  be  dropped  into  place."  (W.  H.  Y. 
Webber.) 

In  Gadd  and  Mason's  spiral  guided  gasholders  the  guides  are 
usually  set  an  angle  of  45°. 


To  obtain  Weight  of  any  Holder. 

Diameter2  x  pressure   in   ^th    inch  x  '4091  =  weight    of    holder 
in  pounds. 


WEIGHT    OF   HOLDERS. 


221 


Diagram  of  Pressures  thrown  by  Holders  of  Different  Weights  and 
Diameters;  also  Weights  of  Holders  per  one-tenth  and  1  inch 
Pressures. 


20000 

19000 
18000 
17000 

16000 
15000 

14000 

g  13000 
9 

£  I2OOO 

•g 

.S  1 1000 

5 

"'-  10000 

a 

J  9000 

a 

^  8000 


6000 
5000 
4000 

3000 

2000 


160000 
150000 
140000 
130000  « 

120000  £ 
I I 0000  C 
lOOOOO  ^ 

90000-^ 

£ 

80000  .SP 

70000 

60000 

50000 

40000 

30000 

20000 


40          60          80         loo         120         140         160         180        200 
Diameters  in  feet. 


GAS    ENGINEERS    POCKET-BOOK. 


To  obtain  Pressure  which  a  Holder  will  throw. 

Weight  of  holder  in  Ibs. 

Diameter*  x  '4091  --  =  Pressure  in  *th  inch« 


Weight  and  Pressure  of  Holders. 


W=P  X  area  X  5-21. 


area  X  5-21 
Formula  for  Computing  Strength  of  a  Cylindrical  Beam  (Cantilever), 


I  =  length  of  beam  in  inches  ;  W  ==  weight  or  pressure  in  pounds, 
which  will  just  break  it. 

S  =  coefficient  of  resistance  to  cross  breaking  or  modulus  of 
rupture. 

I  =  moment  of  inertia  of  the  section  of  the  beam  about  its  neutral 
axis. 

x  =  distance  in  inches  of  the  neutral  axis  from  the  extreme  fibre  of 
the  cross  section.  (W.  H.  Y.  Webber.) 

Herr  Reissner's  Eule— Gasholders. 
Eighty  per  cent,  of  the  greatest  daily  make  as  a  minimum. 

Formula  for  Strength  of  Columns  in  Multipost  Type  of  Gasholders. 

Cripps'  rule  for  the  bending  moment  at  foot  of  one  column  or 
standard  in  foot  tons,  when  there  is  only  1  lift  and  1  tier  of  girders, 
and  framing  is  carried  full  height  of  holder — 

Diar.  of  outer  lift  in  feet  x  total  depth  of  holder  when  up  in  feet.2 
Number  of  columns  X  100 

If  1  tier  girders  and  2  lifts  X  '06 
„  2    „         „          ,    2    „     X  '5 
„  2    „        „          „    3    „     X  '4 

„  3    „         „          „    3     „     X  "34 

Diagonal  ties  increase  strength      .  ...    §th  to  £th 

Strong  cups  and  curbs  increase  strength  .  .  .  .  ^th 
Sheltering  holder  will  increase  strength  ....  £th 
Exposed  to  winds,  holder  strength  will  be  decreased  .  £th 
Shallow  girders  badly  attached  will  be  decreased  .  ith  to  ith 
Standards  lacking  lateral  or  side  stiffeners  will  be  decreased  ith 
Bad  workmanship,  holder  strength  will  be  decreased  ith  to  ith 


GASHOLDER    FRAMING.  223 


Moment  of  Resistance  of  Round  Cast  Iron  Columns. 
Sectional  area  of  column  in  sq.  ins.  X  diar.  of  column  in  ft. ,.     ,  , 

FG 

Moment  of  Resistance  of  Latticed  or  Web  Plate  Standards  of 
Symmetrical  Cross  Section. 

Wrought  iron  equals  effective  sectional  area  of  back  flange  in  square 
inches  X  depth  of  standard  from  front  to  back  in  feet  X  5. 

Steel  equals  effective  sectional  area  of  back  flange  in  square  inches 
X  depth  of  standard  from  front  to  back  in  feet  X  8. 

Moment  of  Resistance  of  Unsymmetrical  Web  Plate  Standards. 
Effective  sectional  area  of  one  flange  X  distance  of  centre  of  gravity 


of  cross  section  of  standard  in  feet  x  j|»^  ^p""  "'""[  X  2  = 
moment  of  resistance.     (Deduced  from  Cripps.) 

For  reasons  of  above  and  further  information  on  gasholders'  guide 
framing,  see  Cripps  on  the  "  Guide  Framing  of  Gasholders." 


GASHOLDERS  OF  CANTILEVER  TYPE. 

Overturning  moment  of  wind  and  snow  = 

8  X  diar.  of  col.  circle  in  ft.  x  depth  of  holder  in  ft.2  + 


diar.  of  col. 
circle  in  ft.3 


2,240 
=  foot  tons. 

Sectional  Area  of  Single  Column  or  Standard  to  Resist  Dead  Load. 

24  x  depth2  +  diameter2 
For  cast    iron,     3>360  x  No.  of  columns   =  sectional  area  required. 

24  x  depth2  +  diameter2 
For  wrot.  iron.     g  n<n — Ss — -= — ; —     —  = 
5,040  x  No.  of  columns 

24  x  depth2  +  diameter2 
'  6,720  x  No.  of  columns   =        »  "          » 

Bending  Moment  Due  to  Distorting  Influence. 

Distance  centre  to  centre  of  standards  x  height2 .     , 

270 

Moment  of  Resistance  to  Distorting  Influence. 
Distance  of  centre  of  gravity  of  standard  from  back  flange  x  effec- 
tive sectional  area  of  back  flange  x  2  x  j  *'  !J  Brought  iron. 

j  8,  if  steel.  (Cripps.) 


224  GAS  ENGINEER'S  POCKET-BOOK. 

Formula  for  Vertical  Sheer. 

24  x  depth2  +  diameter2 

10,000  -  =  foot  tons. 

This  must  be  resolved  in  direction  of  tie  rods  and  struts,  and 
divided  into  the  different  panels  according  to  their  number,  in  the 
proportion  of  1  +2  +  3+4,  &c.  =  x.  Therefore  tension  in  top  tie 

rod  =  —  x  resolved  sheer  in  direction  of  tie  rods,  by  which  strength 

•Z? 

necessary  in  each  tie  rod  may  be  calculated. 

And  for  calculating  strength  for  each  strut,  -  x  resolved  sheer  in 

x 

direction  of  struts.    (Cripps.) 


NOTES  ON  CUPS  AND  GRIPS. 

Weight  of  steel  forming  crown  curb  of  5J  million  holders  at  Old 
Kent  Koad  equals  8  per  cent,  of  the  floating  weight. 

Depth  of  cup  must  allow  for  evaporation  and  tilting  of  holder. 

Cups  and  grips  usually  have  half-round  iron  as  a  bead  riveted  at 
edges. 

Two  channel  irons  have  been  used  by  Mr.  C.  Woodall,  one  at  each 
end  of  first  row  of  crown  sheets,  joined  underneath  by  a  second  plate 
to  form  a  box  girder  to  resist  compressional  strains. 

Use  strong  bottom  curbs  and  well  adjusted  rollers  to  them. 

Blocks  should  be  fastened  in  bottom  of  all  cups  for  grip  of  next 
outer  lift  to  rest  on. 

Guide  rollers  and  carriages  should  be  made  strong  enough  to  resist 
sudden  strains,  especially  if  no  provision  has  been  made  for  keeping 
them  always  close  up  to  the  guides. 

The  pin  should  be  fixed  and  the  guide  roller  revolve  upon  it. 

Rule  for  determining  the  stability  of  the  inner  lift  when  cupped  — 
D2  x  16  must  not  exceed  weight  hanging  on  the  inner  lift  in  pounds. 
D  =  depth  in  feet. 

Steam  should  be  run  into  lute  at  distances  of  not  more  than  200 
feet  apart,  and  this  can  be  made  to  raise  the  temperature  of  the  water 
to  50°  F. 

Inlet  and  Outlet  Pipes  to  Holders  should  be  of  such  size  as  to  allow 
a  maximum  velocity  of  16  feet  per  second  when  the  gas  is  passing 
through  them. 

Horizontal  and  Compression  Strains  in  tons  on  crown  curb  and  on 
any  one  section  of  same,  taken  at  any  point,  clear  of  all  cover  plates 

/Vertical  effective  pressure  in  tons  on  ^th  crown  area  x  diameter  _ 
\  4  versed  sine 

Vertical  effective  pressure  in  tons  on  Jth  crown  area  x  versed  si 
diameter 


STRAINS   ON    GASHOLDER   SHEETING.  225 

or, 


(T- 


vertical  effective  pressure  in  tons  on  |th  crown  area  X  \ 

2  versed  sine  )  0'64 


diameter' 
or, 

aDiar- ) 2  .     A  effective  pressure  of  gas  in  Ibs.  per  square 

2     f    -vei.   smey  foot  of  crown  X  2  versed  sine 

8  versed  sine 

Tension  strain  on  one  foot  vertical  of  side  plates  in  tons  =  S  = 

Diameter 
x  pressure  of  gas  per  square  foot  of  crown  and  s,ide  sheets 

2,210 

Radius  of  crown  in  feet  =  R  = 

Diameter2        versed  sine 


8  versed  sine  '  2 

or, 

Diameter2 

H x  versed  sine2 

2  versed  sine 

Mr.  Wyatt  says  that  not  more  than  33  per  cent,  of  the  strength  of 
the  solid  unpunched  plate  is  obtained  by  ordinary  riveted  gasholder 
sheet  joints,  and  suggests  using  a  double  line  of  rivets  to  the  joints, 
say,  |  inch  diameter  for  i  inch  plates,  put  in  hot  without  tape,  and  a 
thick  coat  of  red  lead  paint  in  the  joint ;  lap  say,  1|  inch  ;  centre  to 
centre  of  rivets  diagonally,  1|  inch ;  centre  to  centre  of  rivets  longi- 
tudinally, 1|  inch  ;  distance  between  centres  of  rows  of  rivets,  T9g  inch  ; 
by  which  means  about  70  per  cent,  of  the  strength  of  the  plate  may 
be  obtained. 

Ordinary  practice  is  single  riveting  equal  to  50  per  cent,  strength  of 
plate  in  gasholder  work. 

Wyatt' s  Rules  for  Strains  in  Gasholders. 

Tangential  tension  strain  in  tons  from  ^th  crown  area  (  =  portion 
acting  on  one  sectional  area  of  crown  curb)  =  T  = 

Vertical  effective  pressure  in  tons  on  ith  crown  area  x  diameter  of 

holder  in  feet      

4  versed  sine  (rise  in  crown) 
or, 

Vertical  effective  pressure  in  tons  on  ith  crown  area  x  radius  of 

_        crown  in  feet 

£  diameter 

O.E.  O 


226  GAS  ENGINEER'S  POCKET-BOOK. 

Tangential  tension  strain  in  tons  on  1  foot  length  of  crown  sheet- 
ing, taken  in  any  direction  and  also  on  1  foot  of  crown  curb 
=  T'  = 

( /diameterX  "  ,    .      )       (effective  pressure  of  gas  in  Ibs. 

\  ^ 2 )  J       I        Per  square  foot  of  crown 

4  X  versed  sine 
or, 

effective  press,  of  gas  in  Ibs.  per  sq.  ft.  of  crown 
Radius  of  crown  in  ft.  X  —  2 

2,240 
or, 

Tangential  tension  strain  in  tons  from  |th  crown  area 
£th  circumference  of  holder 

To  find  the  thickness  of  Crown  Sheets  (safe  strain  =  5  tons  per 
square  inch)  add  the  square  of  half  the  diameter  of  holder  to  the 
square  of  rise  of  crown,  and  multiply  the  sum  by  the  effective  pressure 
of  gas  in  pounds  per  square  foot,  and  divide  the  result  by  5376  times 
the  rise,  multiplied  by  the  percentage  which  the  strength  of  joint  bears 
to  the  solid  plate.  It  is  necessary  to  allow  something  for  wear  and 
tear,  oxidation,  unsound  joints,  riveting  to  thick  plates,  &c.  (F.  S. 
Cripps.) 

To  find  the  shearing  strain  on  the  rivets  in  top  sheets  per  foot  lineal, 
add  the  square  of  half  the  diameter  of  holder  to  the  square  of  rise  of 
crown,  and  multiply  the  sum  by  the  effective  pressure  of  gas  in  pounds 
per  square  foot,  and  divide  the  result  by  four  times  the  rise  =  strain. 
(F.  S.  Cripps.) 

Mr.  Livesey  found  an  average  contraction  on  a  holder  180  feet 
diameter  of  0*6125  inch  on  lifting  the  inner  holder,  a  further  con- 
traction of  0*3375  inch  on  lifting  the  outer  holder,  making  a  total 
contraction  of  0*95  inch,  of  which  0*169  inch  contraction  remained 
as  a  permanent  contraction  when  the  holders  were  again  landed. 

The  cup  and  lower  curb  plate  should  be  made  stronger  than  the 
rest  as  they  cannot  be  painted. 

It  can  be  shown  that  only  a  few  of  the  outer  rings  of  crown  sheets 
are  in  compression,  say  two  or  three  rows  and  one  row  of  side  sheets. 


Fornmla  to  Obtain  the  Tension  on  the  Sheet  Iron  next  Curb. 
(Arson.) 

Weight  of  sides 

TT  diameter  X  sin.  of  angle  of  top  sheets  with  horizontal 

Formula  to  Obtain  the  Tensile  Stress  on  the  Eivets.     (Arson.) 

Weight  of  sides 

r-  cos.  of  angle. 


STRAINS    ON    GASHOLDER   CURBS,  227 

Formula  to  Obtain  the  Crushing  Stress  on  the  Curb.     (Arson.) 
Weight  of  sides 


18-3 


angle  of  top  sheets  with  horizontal 


Eule  to  Find  the  Compressive  Strain  on  a  Gasholder  Curb. 

(Half  the  diameter  of  holder3  -  rise2)  x  pressure  of  gas  in  Ibs.  per 

square  foot  x  diameter  of  holder  

Kise  x  8 

Strain  (compressive)  in  pounds  due  to  the  pull  of  the  top  sheets  ;  to 
this  add  depth  of  inner  lift  X  6 '5  X  diameter  of  holder  for  the 
pressureof  wind,less  diameter  of  holder  x  depth  x  actual  pressure 

10  or  lo 
of  gas  for  the  pressure  of  gas  on  the  sides. 

The  constant  10  is  used  for  vertical  stays  fastened  all  the  way  up. 
The  constant  16  is  used  for  vertical  stays  loose.  Difference  equals 
compressive  strain  on  top  curb,  (Deduced  from  Cripps.) 


Q  2 


228  GAS  ENGINEER'S  POCKET-BOOK. 

WORKSHOP  NOTES. 

Wyatt's  Rule, — Three  hundred  and  seventy  cubic  feet  of  work- 
shops  and  offices  required  per  ton  per  diem  (dwelling-house  included), 

Best  Speed  for  Cutting  Tools  when  Working. 
Steel        .        .        .12  feet  per  minute. 
Cast  iron      .        .        18    „  „ 

Brass  ,     24     „  „ 

Wrought  iron       ,         24     „  „ 

Wood       .        .        2,000    „  „         when  material  revolves. 

„  .        .     3  000     „  „          when  tool  revolves. 

Grindstone       .        .  800     .,  „ 

Circular  saws  should  be  run  at  about  9,000  feet  per  minute  on  the 
teeth. 

Band  saws  should  be  run  at  about  4,000  feet  per  minute. 
Planing  and  moulding  rotary  cutters,  5,000  feet  to  7,000  feet  pel 
minute  on  cutting  edge. 

Emery  discs,  4,000  feet  to  6,000  feet  per  minute  on  periphery. 
Drills  for  wrought  iron  should  have  circumferential  speed  of  140  to 
160  inches,  and  for  cast  iron  80  to  120  inches. 
Another  authority  gives — 

Speed  of  Cutting  Tools. 

For  Cast  iron 150  to  190  inches  per  minute. 

„       „    (boring) 80 

Wrought-iron     ....  200  to  280 

Yellow  brass 300 

Band  saw  for  metal    .        .        .        .250  feet 

„       „       „    wood       .         .         .         4,000 
Teeth  of  circular  saws       .        .        .    9,000 
Cutter  blocks  for  planing  and  mould- 
ing wood  (cutting  edge)        .         .    6,000     „  „ 
Irregular    moulding     and     shaping 

machines,  wood  (cutting  edge)      .    5,000    „  „ 

Saw  and  cutter  sharpening  machine     5,000     „  „ 

General  Notes. 

A  man  will  pull  or  exert  an  effective  power  of  35  Ibs.  in  fair  working. 

Angles  of  cutting  tools  : — Wood,  30  to  40  degrees  ;  wrought  iron, 
GO  degrees  ;  cast  iron,  70  degrees  ;  brass  80  degrees. 

Circumferential  velocity  of  drill  should  equal  about  100  inches  per 
minute  for  cast  iron  and  150  inches  for  wrought  iron. 

Circumferential  speed  of  emery  wheels,  about  5,000  feet  per  minute. 
„  „  of  grindstones,  „  800  .,  „ 

The  diameter  of  the  hole  in  the  die  should  exceed  the  diameter  of  the 
punch  by  about  one  fifth  of  the  thickness  of  the  metal  to  be  punched. 

The  die  first  used  was  36  millimetres  in  diameter ;  afterwards  one 
of  39  millimetres  in  diameter  was  substituted  without  altering  the 
size  of  the  punch.  The  hole  made  with  the  36-millimetre  die  under- 
neath was  cylindrical,  but  with  the  39-milliinetre  die  it  was  conical. 


STATION    METERS. 


229 


The  amount  of  clearance  between  punch  and  die  should  equal 
one  fifth  the  thickness  of  metal  to  be  punched. 

Two  pieces  of  aluminium  or  platinum  pressed  together  for  eight 
hours  at  330°  C.  will  cohere. 

Iron  castings  contract  about  |th  inch  per  foot ;  brass  castings,  about 
^ths  inch  per  foot. 

Allow  frds  of  the  width  of  rails  for  mortices  and  ^rd  for  haunching. 

Approximate  quantity  of  air  required  for  welding  in  a  smith's 
forge  equals  about  150  cubic  feet  per  minute. 

Station  Meters. 

Choose  a  station  meter  in  which  the  spout  is  kept  wen  above  the 
water  line,  and  see  that  the  bearings  and  stuffing  box  can  easily  be 
got  at  for  examination  and  repair.  See  that  no  useless  metal  is  put 
into  the  drum,  causing  weight  and  consequent  pressure  to  turn. 
Have  sufficiently  large  openings  in  the  hoods  to  allow  an  easy 
passage  of  the  gas  on  both  inlet  and  outlet  ends  of  the  drum. 

To  Find  the  Capacity  of  a  Station  Meter  Drum. 

Find  the  area  of  a  circle  of  equal  diameter  to  the  diameter  of  the 
drum  (a).  Multiply  by  the  average  depth  from  centre  of  hood 
space  on  outlet  end  to  centre  of  hood  space  on  inlet  end  (&)  above 


—  * 


the  water  line,  and  deduct  from  this  a  square  equal  to  twice  the 
water  line  above  the  centre  of  the  drum  (d)  multiplied  by  length 
from  inlet  to  outlet  sides  of  drum  on  water  line  (e). 

Herr  Reissner's  Rule— Station  Meters. — Allow  80  revolutions  per 
hour  as  a  maximum. 


230 


GAS  ENGINEER'S  POCKET-BOOK. 


The  openings  in  the  centres  of  station  and  other  meters  should  be 
such  as  to  allow  the  water  to  pass  easily  from  one  chamber  to 
another,  so  as  to  relieve  the  pressure  upon  the  partition.  The  same 
applies  to  the  raising  of  the  water  line,  which  may  cause  the  immer- 
sion of  the  partitions  to  such  an  extent  as  to  cause  a  perceptible  drag 
on  the  revolution  of  the  drum. 

Dimensions  of  Square  Station  Meters. 


Capacity  per 
Hour  at  100 
Revolutions. 

Capacity 
per 
1  Revo- 
lution. 

Side  to 
Side. 

Front  to 
Back. 

Height. 

Diameter 
of 
Drum. 

Length 
of 
Drum. 

Diame- 
ter of 
Connec- 
tions. 

Ft.    Ins. 

Ft.    Ins. 

Ft.    Ins. 

Ft.    Ins. 

Ft.    Ins.  Inches. 

20,000 

200 

9     3 

8     6 

9     6 

8     0 

7      6 

12 

25,000 

250 

9     3 

9     3 

9     6 

8     2 

8     0 

12 

30,000 

300 

10     0 

10     0 

10     9 

8     7 

8     6 

14 

40,OCO 

400 

11     8 

11     3 

12     0 

9     9 

9     0 

15 

50,000 

500 

12     0 

12     0 

13     0 

10     6 

10     6 

16 

60,000 

600 

12     0 

13     0 

13     0 

10     6 

11     6 

18 

80,000 

800 

13     6 

13     6 

14     0 

12     0 

11     6 

20 

100,000 

1,000 

15     4 

15     0 

16     6 

13     (> 

11     6 

24 

125,000 

1,250 

15     4 

15     0 

16     6 

14     0 

12     4 

24 

150,000 

1,500 

15     6 

17     6 

15     5 

13     6 

14     2 

24 

250,000 

2,500 

20     6 

19     3 

21     0 

18     0 

15     0 

30 

Round  Station  Meters. 


Capacity  per 
Hour. 

Capacity  per 
Revolution. 

Diameter 
Inside. 

Depth 
Inside. 

Diameter  of 
Flanges. 

Diameter 
of  Con- 
;  nections. 

Ft.  Ins. 

Ft.  Ins. 

Ft.  Ins. 

Inches. 

600 

5 

2     3 

2     3 

2     9 

2 

900 

7-5 

2  10 

2    3 

3     4 

3 

1,200 

10 

3     2 

2    8 

3     8 

3 

1,500 

12-5 

3     4 

3     0 

3  10 

4 

1,800 

15 

3     6 

3     4 

4     0 

4 

2,400 

20 

3     9 

3     6 

4     Bi 

4 

3,000 

25 

4     0 

4     0 

4     7 

5 

3,600 

30 

4     3 

4     2 

4  10 

6 

4,000 

40 

4     9 

4     6 

5     4 

6 

5,000 

50 

5     0 

4     8 

5     7 

6 

6,000 

60 

5     0 

5     4 

5     7 

8 

7,000 

70 

5     6 

5     6 

6     1 

8 

8,000 

80 

5  10 

5     8 

6     5 

8 

10,000 

100 

6     4 

6     2 

6  11 

9 

12,500 

125 

6  10 

6     2 

7     5 

10 

15,000 

150 

7     0 

7  10 

7     7 

10 

17,500 

175 

7     3 

7     6 

7  10 

12 

20;000 

200 

8     0 

7     6 

8     7 

12 

25,000 

250 

8     0 

9     6 

8     7 

12 

30,000 

300 

8     5 

9     8 

9     0 

14 

MANUFACTURING.  231 


STORING  MATERIALS. 

Coal  when  exposed  to  the  air  changes  m  character,  the  change 
consisting  in  a  diminution  of  agglomerating  as  well  as  of  lighting 
power,  and  probably  also  of  heating  power. 

The  change  is  more  rapid  the  higher  the  temperature  and  the 
more  divided  the  coal. 

In  the  small  pieces  the  change  in  the  character  of  the  coal  is 
greater  on  the  surface  than  in  the  interior.  In  heaps  of  coal  per- 
meated by  the  air  the  change  is  greater  in  the  centre  than  on  the 
surface.  When  the  air  cannot  penetrate  to  the  centre  the  surface 
undergoes  the  greatest  change. 

Small  coal  washed  is  less  liable  to  change  than  unwashed. 

Large  pieces  of  coal  are  only  liable  to  change  after  a  certain 
number  of  years'  exposure  to  the  air.  The  small  coal  is  affected  very 
quickly  if  it  happens  to  be  under  conditions  likely  to  raise  its 
temperature. 

In  a  few  months  it  is  capable  of  entirely  losing  its  agglomerating 
and  lighting  power.  Heaps  of  small  coal  become  heated,  but 
stacks  of  large  coal  do  not  heat  to  an  appreciable  degree. 

Small  coal  should  not  be  stacked  in  too  large  heaps. 

Coal  stacked  in  low  heaps  does  not  become  heated.  Heat  increases 
with  the  height  of  the  stack,  and  at  about  the  height  of  3  or  4  metres 
the  temperature  rises  progressively  and  then  descends  without  having 
exceeded  60°  C.  or  70°  C. 

The  inner  temperature  of  a  stack  2  metres  high  does  not  usually 
exceed  40°  C.  to  50°  C.  (M.  de  Lachomette.) 

Storing  coal  in  the  open  may  cause  a  loss  of  from  30  to  40  per  cent, 
in  the  quantity  of  gas  to  be  obtained  from  it. 

North  Wales  coals  and  certain  cannels  are  said  not  to  depreciate 
appreciably  through  exposure  when  stored  in  the  open,  while  certain 
Scotch  coals  have  been  known  to  lose  50  per  cent,  in  value  in  3  months. 

All  coals  exposed  to  the  air  absorb  oxygen,  the  volume  of  which 
may  be  100  times  that  of  the  coal. 

The  loss  and  increase  of  weight  are  produced  more  slowly  the 
larger  the  pieces  of  coal.  (M.  de  Lachomette.) 

The  yield  of  gas  from  coal  before  exposure  being  equal  to  26*36, 
fell  to  6-60  after  being  subjected  for  4  days  to  400°  C.,  and  at  8  days 
to  nil.  The  illuminating  power  also  diminishing  very  quickly. 
(M.  de  Lachomette.) 

Powdered  coal  containing  from  1*6  to  8'3  per  cent,  oxygen  when 
subjected  to  the  prolonged  action  of  air  and  of  stagnant  and  running 
water  is  not  appreciably  affected  with  regard  to  composition,  yield  of 
coke,  or  calorific  power.  (M.  Georges  Arth.) 

The  drier  the  coal  when  stacked  the  less  the  liability  to  heat,  and 
all  trampling  or  compression  should  be  avoided. 

The  only  thing  to  be  done  with  heated  coal  is  to  open  it  out  and 
allow  it  to  cool,  or  the  heating  will  spread. 

M.  Morin  suggests  connecting  the  two  ends  of  a  thin  platinum  wire, 
about  0-0008  inch  diameter,  laid  through  the  thermometer  to  a 


232  GAS 

battery  and  galvanometer,  when  the  varying  resistance  due  to  the 
rise  and  fall  of  the  mercury  will  be  shown  upon  the  galvanometer, 
and  the  temperature  of  anything  may  be  observed  at  a  distance,  such 
as  in  a  heap  of  coals. 

Another  form  of  indicator  for  showing  when  coals  are  heated  above 
a  certain  temperature  might  be  made  by  means  of  the  two  wires 
from  a  battery  covered  with  gutta-percha  and  the  one  wound  round 
the  other,  so  that  when  a  sufficient  heat  was  formed  to  melt  the 
covering  the  two  wires  would  be  in  contact,  and  could  be  made  to 
Aug  an  electric  bell. 


Igniting  Points  of  Coals.     (V.  B.  Lewes.) 

Cannel        .        .        .     098°  F.  =  370°  C. 

Hartlepool  .        .     .     760° .,  =  408°  „ 
Lignite        .        .         .     842°  „  ==  450°  „ 

Welsh  steam  .        .     .  870J°  „   =  477°  „ 

When  Wire  Ropes  have  to  run  over  small  pulleys  or  capstans  the 
number  of  wires  should  be  increased.  In  the  case  of  cranes  sometimes 
as  many  as  270  are  used. 

Average  consumption  of  Coal  per  Passenger  Train  Mile  equals  30  Ibs., 
or  about  1£  Ib.  to  If  Ib.  for  hauling  10  tons  1  mile.  Consumption  of 
coal  per  square  foot  of  firegrate  per  hour  varies  from  60  Ibs.  to  80  Ibs. 

When  large  Stocks  of  Coke  are  stored  in  the  open  an  increase  in 
weight  of  15  to  20  per  cent.,  due  to  wet  weather,  has  at  times  been 
found.  (C.  Gandon,  Gas  Institute.  1887.)  See  also  p.  145. 

Stacking  coke  in  large  quantities  deteriorates  the  quality. 

100  Ibs.  coke  can  absorb  50  Ibs.  water. 

Increased  quantity  of  breeze  due  to  use  of  coke  breaker  only 
about  5  per  cent,  of  coke  broken,  or  1  cwt.  per  ton  of  broken  coke  for 
sale.  Less  when  broken  while  warm  (say  1£  bushels  per  ton). 

Oils  flashing  below  73°  F.  are  not  allowed  to  be  stored  in  warehouses 
or  shops  in  England. 


CARBONIZING.  233 


RETORT  HOUSE  MANUFACTURE, 

The  gas  produced  in  part  of  the  retort  nearest  the  front  is  not 
usually  so  good  in  quality  or  quantity  as  that  from  other  parts. 

Uneven  charging  reduces  the  temperature  of  the  retorts  and  makes 
a  poorer  coke. 

Uneven  charges  cause  the  evolution  of  gases  of  little  or  no  illu- 
minating power  from  the  thin  portion,  while  the  thicker  portion  is  not 
properly  burnt  off  in  the  allotted  time,  and  gas  is  lost. 

Retorts  which  allow  but  little  room  above  the  coals  are  to  be 
preferred,  as  then  the  gas  passes  quickly  away  from  contact  with  the 
heated  surface  of  the  retort,  which  causes  the  decomposition  of  some 
of  the  olefiant  gas. 

The  production  of  the  hydrocarbon  compounds  from  the  coal  takes 
place  at  a  comparatively  low  temperature  ;  these  hydrocarbon  com- 
pounds are  then  broken  up  into  simpler  forms  by  the  passage  through 
the  retort  and  exposure  to  its  heated  sides. 

Deep  charges  cause  caking  of  the  outer  portion  before  the  inner  is 
worked  off,  the  outer  portion  having  been  quickly  gassified.  The  coke 
then  is  giving  off  sulphur.  The  thick  charge  cools  the  retort,  and 
the  gas  then  made  is  less  and  the  tar  high.  (GL  Anderson.) 

Charge  should  fill  the  retort  as  full  as  will  allow  convenient 
charging  and  drawing. 

Deep  charges  of  coal  cause  caking  on  the  exterior  for  some  hours 
before  the  interior  of  the  charge  is  worked  off. 

The  whole  of  the  outer  surface  is  giving  off  sulphur  for  some  hours 
after  it  has  given  off  its  gas. 

The  large  mass  cools  the  retorts  for  some  time,  while  tarry  vapours 
are  being  formed  instead  of  gas. 

Large  retorts  at  low  heats  conduce  to  deposition  of  soot  and 
napthalene. 

The  sulphur  given  off  from  damp  coals  is  greater  than  from  dry. 

At  high  temperatures  the  gas  produced  contains  methane  (CH^.)  and 
free  H  ;  and  more  free  C  in  the  tar  and  in  the  compounds  of  carbon 
belonging  to  the  aromatic  series  derived  from  benzene  (C6H6)  and  H 
is  separated,  and  napthalene,  anthracene,  phenanthrene,  chrysene, 
&c.  are  formed.  (Dr.  Lunge.) 

At  low  temperatures  the  hydrocarbons  formed  belong  to  the 
paraffin  series  (methane),  having  the  general  formula  CnH2n  +  2,  along 
with  olefines  (C^H2%).  (Dr.  Lunge.) 

With  low  heats  the  yield  of  ammonia  is  generally  lower,  which  is 
also  the  case  with  high  makes. 

Low  temperatures,  with  9,000  c*ubic  feet  of  gas  per  ton,  will  yield, 
with  a  certain  coal,  16  gallons  tar,  but  the  same  coal  at  high  tempera- 
tures will  yield  9  gallons  tar  and  11,000  cubic  feet  of  gas.  (Davis.) 

If  coal  were  distilled  at  low  temperatures  and  the  gases  afterwards 
subjected  to  greater  heat  in  separate  retorts,  where  the  heat  could  be 
accurately  controlled,  better  results  might  accrue.  (Foulis.) 

Mr.  Hunt,  testing  in  a  small  iron  retort,  found  that  the  greatest 
number  of  candles  per  ton  was  obtained  with  a  temperature  of 


234  GAS  ENGINEER'S  POCKET-BOOK. 

1,600° F.,  and  he  considers  the  best  heat  for  ordinary  working  is  the 
lowest  that  will  thoroughly  carbonize  in  the  allotted  time,  the  stopped 
pipes  with  high  heats  causing  loss  beyond  the  gain  by  the  higher 
temperatures. 

There  is  a  certain  temperature  at  which  each  coal  may  be  made  to 
yield  the  best  results,  both  as  to  quantity  and  quality. 

When  gas  is  being  evolved  from  coal  the  temperature  of  the  retort 
is  not  even  along  the  length  of  the  retort. 

When  a  substance  is  subjected  to  a  high  heat  and  to  an  advanced 
state  of  decomposition  the  products  produced  are  generally  of  a 
simple  nature. 

The  higher  the  heats  the  greater  the  proportion  of  hydrogen  and 
methane  and  the  lower  that  of  C. 

Temperature  in  retorts  =  1,800°  to  2.000°  F.  =  temperature  in 
hydraulic  main  of  only  140°  to  180°  F.  =  110°  to  150°  F.  at  outlet  of 
latter.  (J.  Hornby.) 

Temperature  in  retorts  rarely  more  than  2,2CD°  F. 

Cherry  red  is  the  best  heat  for  iron  retorts. 

A  good  orange  is  about  right  for  clay  retorts. 

If  the  heat  of  retorts  is  1.000°  C.  (1,832°  F.)  before  the  charge  is 
in  the  heat  of  the  coals  near  the  walls  will  be  about  800°  C.  (1472°  F.) 
and  in  the  centre  of  the  coals  400°  C.  (752°  F.). 

The  upper  layer  of  evolved  gas  will  be  at  a  temperature  of  1,000°  C., 
and  the  lower,  near  the  coal,  600°  C.  (1,112°  F.)  (Prof.  Lewes.) 

If  a  long  piece  of  gas  piping,  closed  at  one  end,  is  passed  through 
a  hole  in  the  retort  lid  with  the  open  end  to  the  air  it  can  be  used  to 
obtain  the  heat  of  the  retort  at  different  points.  (L.  T.  Wright.) 

The  velocity  of  gas  in  its  passage  through  highly  heated  retorts  is 
about  5  feet  per  second  during  the  maximum  evolution  of  the  gas. 

Damp  coals  cause  steam  in  the  retort,  which  is  afterwards  condensed 
in  the  condensers,  and  which  has  a  tendency  to  lower  the  tempera- 
ture of  the  retort. 

Loss  between  working  in  summer  and  winter  equals  9*6  per  cent, 
in  favour  of  the  former,  in  the  sperm  value  obtained  from  similar  coals. 

Very  high  yields  of  gas  are  only  obtainable  with  excessive  use  of  fuel. 

Clay  retorts  usually  worked  at  1,082°  C. 

At  a  yield  of  118  cubic  feet  per  square  foot  of  retort,  cast  iron 
could  be  melted  (=  +  2,100°  F.)  in  the  top  flue,  and  silver  in  the 
bottom  flue  (  =  +  1,749°  F.). 

The  greater  proportion  of  the  CS2  is  formed  after  the  useful  gases 
have  been  driven  off  from  the  coal,  and  is  increased  if  the  coal  be  wet 
when  put  in  the  retort. 

Best  temperature  for  Newcastle  coal  is  dull  orange  or  2,010°  F. 

Clay  retorts  are  bad  absorbers  of  heat  compared  with  iron  retorts. 

Water  vapour  in  the  retort  seems  to  have  some  protective  action  on 
napthalene.  (L.  T.  Wright.) 

The  maximum  production  per  square  foot  of  retort  surface  may  be 
taken  as  126  cubic  feet  per  ton,  or  14-7  tons  of  coal  carbonized  per 
1,000  square  feet  per  24  hours. 

There  are  certain  paraffin  hydrocarbons  in  the  coal  which  are 
split  up  into  simpler  members  of  the  same  series  and  into  olefinea 


TEMPERATURE   OP    DISTILLATION. 


235 


Fractional  distillation  is  a  means  of  separating  liquids  with  boiling 
points  at  least  30°  F.  apart. 

Cannel  coal  carbonizes  in  about  five-sixths  the  time  of  caking  coal, 
and  the  greatest  quantity  of  gas  is  evolved  during  the  first  hour  of 
charge. 

Temperature  of  gas  as  it  leaves  the  coal  about  170°  F. 

The  more  rapidly  the  coal  is  carbonized  the  better  are  the  results. 
(W.  Foulis.) 


Products. 

Percentage  of 
Coal. 

Calories  per  ton 
of  the  Coal. 

Percentage  of  Heat  of 
Combustion  of  Coal. 

Coke  .     .     . 

65-66 

4,682,683 

62-09 

Gas  (Dry)  . 
Tar    ... 

17-09 
7-81 

1,929,252 
671,231 

25-58 
8-90 

Loss     .     .  . 

258,866 

3-43 

1 

7,542,032 

100-00 

Loss  occurs  through  the  endothermic  process  of  carbonization,  as 
the  coal  appears  to  liberate  heat  and  not  absorb  it.  (Euchene  and 
Mahler's  results.) 

Residuals  and  Impurities  at  Outlets  of  Retorts  in  Percentage  by 
Weight  of  Crude  Gas.     (Prof.  Wanklyn.) 

Tar 33        per  cent 

Watery  vapour 50  „ 

Ammonia 2  „ 

C02 5  „ 

H2S 2  to  5      „ 

S.  as  sulphuret  of  carbon  and  organo-sulphur 

compounds      . '15  to  '3     „ 

Result  of  Heating  to  about  1000°  C.     (Prof.  Lewes.) 
Ethane      becomes  ethylene  and  hydrogen. 
Ethylene         „        methane  and  acetylene. 
Acetylene        „        benzene,  styrolene,  retene,  &G. 
Variation  in  Quantity  of  C02  and  H2S  according  to  the  Heat  of 
Distillation.    (Lewis  T.  Wright.) 


CAKING  COALS. 

Yield  of  Gas 
per  Ton. 

Grs.  of  CO,  per 
Cubic  Foot. 

Grs.  of  HaS  per 
Cubic  Foot. 

7,856 
8,547 
11,128 

16-92 
18-38 
19-37 

3-16 

4-69 
5-87 

CANNEL  COAL. 

7,853 
10,047 

32-60 
39-27 

4-80 
4-97 

The  "salts"  usually  found  mixed  with  tar  in  the  hydraulic  and 
foul  mains  are  probably  sal-ammoniac,  and  are  formed  by  high  heats. 

Crude  gas  contains  about  1  per  cent,  ammonia,  weighing  from 
5J  Ibs.  to  8  Ibs.,  and  about  5  per  cent.  C02  and  H2S. 


236 


GAS  ENGINEER'S  POCKET-BOOK. 


Result  of  Carbonization  at  Different  Temperatures. 
(L.  T.  Wright.) 


Temperature. 

Gas. 
Cubic 
Feet 
perTon 

Illu- 
minat- 
ing 
power 

Candles 
per 
Ton. 

H. 

C«it. 

Me- 
thene 
per 
Cent. 

Ole- 
fines 

Cent. 

CO. 

pei- 
Cent. 

N. 
Cent. 

Dull  red. 
Hotter       . 

Bright  orange 

8,250 
9,693 
10,821 
12,006 

20-5 
17-8 
16-7 
15-G 

33,950 
34,510 
36,140 
37,460 

38-09 
43-77 
Test  1  os 
48-02 

42-72 
34-50 
Testlost 
30-70 

7-55 
5-83 
Test  lost 
4-51 

8-72 
12-50 
Test  lost 
13-96 

2-92 
3-40 
Test  lost 
2-81 

At  a  low  rate  of  distillation  nearly  all  the  gas  is  evolved  at  1,340°  F. 

At  the  highest  rate  of  distillation  66  per  cent,  of  gas  is  evolved  at 
1,339°  F. 

When  the  yield  of  gas  per  ton  is  under  9,000  cubic  feet  the 
temperature  of  the  bottom  flue  is  not  above  1,580°  F.,  but  with  a 
temperature  there  of  1,680°  F.  the  yield  increased  to  9.378  cubic  feet 
per  ton.  (L.  T.  Wright). 


Temperature 
of  Retort. 

Make  of  Gas. 

Gallons  of  Tar. 

Remarks. 

600°  F. 
750°  to  800°  F. 
1000°  F. 
1830°F. 

2010°  F. 

.  Feet  per  ton. 
400 
1,400 
6,000 
8,300 

10,000 

68 
13  to  14  gals. 
9 

coke  very  friable. 

faint  red  heat, 
bright  cherry  red 
heat, 
orange  heat. 

Low  temperatures  give  little  ammonia. 
Medium  temperatures  give  most  ammonia. 

Higher  temperatures  give  rather  less  ammonia  but  more  CS2,  H2S, 
and  cyanogen. 


Make  per  Ton, 
Cubic  Feet. 

NHS  per  Ton. 

Percentage  of  Coal 
asNH3 

11,620 
10,162 
9,431 
7,512 

Ibs. 
7-411 
7-894 
7-504 
6-391 

0-331 
0-352 
0-335 

0-285 

Temperature 
of  Retort. 

Make  of  Gas. 

Illuminating  power 

Illuminants. 

2,000°  F. 
2,160°  F. 

Per  Ton. 
9,800 
11,000 

Candles. 
16-54 
12-00 

Lbs.  Sperm. 
525£ 
452£ 

(L.  T.  Wright.) 


HOURLY   MAKE  OF   GAS. 


237 


Coal  carbonized  at  2,000°  yielding  9,800  cubic  feet  of  lfr-54  candle 
gas  equal  to  555£  Ibs.  illuminating  matter,  but  if  carbonized  at  2,160° 
will  yield  11,000  cubic  feet  gas  of  12  candle-power  equal  to  452£  Ibs. 
illuminating  matter. 

If  caking  coal  be  carbonized  at  600°  F.  (hardly  red  in  a  dark 
place)  only  400  cubic  feet  of  gas  per  ton  are  evolved,  and  most  of 
the  hydrocarbons  are  resolved  into  tar. 

At  low  heats  600°  F.  tar  and  oils  are  formed  but  little  gas,  while 
at  higher  heats  gas  is  formed  with  less  tar. 

At  a  low  red  heat  in  daylight  about  6,500  feet  are  produced  per 
ton. 

At  750°  to  800°  F.  about  1,400  cubic  feet  gas  and  68  gallons  tar 
or  crude  oil  are  given  off ;  at  1,000°  (a  faint  red  in  subdued  day- 
light) about  6,000  cubic  feet  gas  ;  and  at  1,830°  (a  bright  cherry  red) 
about  8,300  cubic  feet  with  13  or  14  gallons  tar  are  evolved  ;  and  at 
2.010°  (orange)  about  10,000  cubic  feet  per  ton  with  9  gallons  tar. 
(Gesner.) 

Composition  of  Gas  from  Newcastle  Coal  Carbonized  at 
Different  Heats.     (Thorpe.) 

Gas  per  ton  of  coal,  cubic  feet      .        .  8,250  9,692  12,006 

Illuminating  power,  candles  .         .     .  20-59  17*80  15*60 

Unsaturated  Hydrocarbons,  per  cent.  7'55  5-83  4-51 

Marsh  Gas 42-72  34-50  30-70 

Carbon  Monoxide       ....  8'72  13'50  13'96 

H 38-09  43-77  48'02 

N.  2-92  2-40  2-81 


Percentage  and  Specific  Gravity  of  Gas  .during  each  of  Five  Hours' 
Charge. 

First  hour      46-6  per  cent,  gas  given  off  '677  average  specific  gravity. 
Second  hour  27-4        „         „         „      „    -419        „  „  „ 

Third  hour    16-0        „          „        „      „    '400        „ 
Fourth  hour   7'3        „          „        „      „    -322        „  „  „ 

Fifth  hour       2'7        „         „        „      „      — 


Another  experiment  gives 

First  hour     51  -3  per  cent,  gas  given  off  specific  gravity  not  taken. 
Second  hour  33-5         „  „         „ 

Third  hour     11-8        „        '  „        „ 
Fourth  hour    3-4         „  „        „ 

1  ton  coal  distilled  a£  about  1,650°  F.  will  be  carbonized  in  6  hours. 
„       „  „         V         2,010°  F. 


The  greatest  quantity  of  gas  from  caking  coal  is  evolved  during 
the  second  hour. 


238  GAS  ENGINEER'S  POCKET-BOOK. 

Wigan  Caunel  (1  ton)  produced 

First  hour 3,320  cubic  feet. 

Second  hour        ....    2,940         „ 

Third  hour 2,660         „ 

Fourth  hour        ....     1,040          „ 

(Herring.) 

Six-hour  Charges. 

At  end  of  first  hour  one-sixth  of  the  total  quantity  of  gas  is  given 
off,  at  commencement  of  second  hour  the  coal  becomes  soft,  and  during 
the  second,  third,  and  fourth  hours  yields  gas  from  innumerable  small 
jets,  at  the  fifth  hour  it  is  compact  and  doughy,  the  gas  issuing  from 
throughout  the  mass.  At  the  commencement  of  the  sixth  hour  it  is 
still  black  as  at  first,  and  the  evolution  of  gas,  which  has  been  fairly 
uniform,  commences  to  decrease  very  rapidly.  At  5£  hours  gas 
almost  ceases  to  issue,  and  coke  becomes  incandescent  and  brittle. 

Quality  of  gas  nearly  uni  form  for  first  five  hours,  but  deteriorates 
greatly  the  last  hour,  often  being  not  more  than  3  candles. 

Four-liour  Charges. 

Periods  of  three-quarters  of  an  hour  correspond  to  those  of  one 
hour  in  above  remarks. 

The  work  done  in  the  retort  during  the  last  hour  of  the  charge, 
amounting  to  about  5  per  cent,  of  the  whole,  is  also  getting  the 
retort  in  a  condition  of  heat  to  receive  the  next  charge.  It  has  been 
proposed  by  the  "  Journal  of  Gas  Lighting  "  to  connect  the  mouth- 
piece of  the  retort  by  means  of,  say,  a  2-inch  or  3-inch  tube,  provided 
with  a  cock,  with  the  interior  of  the  setting,  and  divert  the  gas  yielded 
during  the  last  hour  of  the  6-hour  charge,  so  that  it  may  assist  in 
heating  the  retorts,  and  not  deteriorate  the  quality  of  the  gas  already 
made. 

First  hour  |  volume  of  10  candles  ;  second  hour  and  half,  £  volume 
of  17  to  18  candles  ;  third  hour,  i  volume  of  14  candles  ;  remainder,  8 
to  10  candles  at  high  heats,  making  11,000  feet  gas  of  14  candles. 
(Butterfield.) 

„_,„  Gas  made 

Hours-  percent. 

1  16*6  Gas  strongly  impregnated  with  tar. 

2  .        ...     Coal  becomes  soft. 

3  .        .        .     .    In  a  state  of  intumescence  and 

yielding. 

4  .         .        .        .Gas  from  innumerable  small  jets. 
6        .         .        .     .     A  compact  and  doughy  mass. 

6  .  .  .  .  Coal  still  black,  yield  of  gas 
decreasing  rapidly,  sulphur 
compounds  being  evolved, 
quality  about  3  candles. 


CLIMATIC   EFFECTS   ON    DISTILLATION. 


239 


From  tests  of  a  Scotch  coal,  giving  an  average  of  11,250  cubic 
feet  per  ton  of  30'18  candle  power,  Mr.  W.  Wallace,  F.I.C.,  found  a 
variation  both  in  illuminating  power  and  pounds  of  sperm  per  ton, 
according  to  the  temperature  : — 


Lbs.  Sperm 
per  Ton. 

Illuminating 
Power. 

In  January      . 

1,136 

29-44 

February        .        .     . 

1,140 

29-56 

March 

1,122 

29-08 

April      .         ... 

,135 

29.41 

May   . 

,218 

31-58 

June       .         .         .     . 

,208 

31-32 

July   .... 

,209 

31-34 

August           .         .     . 

,209 

31-34 

September  . 

,178 

30-54 

October  .... 

,146 

29-72 

November  . 

,139 

29-53 

„  December      .        .    . 

,124 

29-14 

Average  . 

1,164 

30-18 

Or  by  temperatures — 


Degrees  Fahr. 

Lbs.  Sperm 
per  Ton. 

Illuminating 
Power. 

36  to  40 

,108 

28-73 

41  to  45 

.        .         .     . 

,124 

29-14 

46  to  50 

,142 

29-61 

51  to  55 

.182 

30-65 

56  to  60 

,206 

31-27 

61  to  69 

.     . 

,215 

31-50 

Average  . 

1,163 

30-15 

Proportions  of  coal,  coke,  and  tar  used  per  ton  in  firing  retorts  : — 

2|  cwts.  of  coke  are  used  per  ton  of  coal  carbonized  with 
gaseous  regenerative  firing. 

3£  to  4£  cwts.  of  coke  are  used  per  ton  of  coal  carbonized  with 
ordinary  furnaces. 

1  ton  of  tar  is  equal  to  about  2  tons  of  coke  in  firing. 

Loss  in  direct  fired  settings  through  heat  dissipated  up  chimneys. 
Of  N  and  C02  or  0  and  CO  =  5943'4  B.T.U.  out  of  14550  B.T.U. 
from  1  Ib.  C,  or  41  per  cent.  Any  increase  of  air  above  the  theoretical 
quantity  required  increases  the  loss  up  the  chimney.  50  per  cent,  is 
usually  the  quantity  lost  as  then  the  excess  air  is  only  20  per  cent. 

Too  little  air  in  direct  fired  settings  reduces  the  heat  per  1  Ib.  fuel 
in  increased  proportions. 


240 


GAS  ENGINEER'S  POCKET-BOOK, 


Pounds  fuel  used  per  100  Ibs.  coal  carbonized  : — 


Coke 
Breeze 


17-36  Ibs. 
2-74  Ibs. 


The  above  are  calculated  from  the  quantity  used  in  a  week  of 
6£  days.— March  21st,  1892. 

Composition  of  Gases  in  Generator  Furnaces. 


EBELMAN'S  GASOGENE.                                               SIEMEN'S  GENERATOR. 

Air. 

Air  and  Steam. 

CO    . 

33-3 

27-2     26-0 

C02        

0-5 

5-5       4.5 

N       

63-4 

53-3     67-5 

0   

— 

—        0-5 

a     

2-8 

14-0       — 

100-0 

100-0    100-0 

First  analysis  most  like  the  exact  chemical  proportions  for  the 
entire  conversion  of  carbon  into  CO  without  C02  which  are  34J  per 
cent.  CO  and  65£  per  cent.  N. 

Amount  of  Primary  and  Secondary  Air  should  be  tried  and  fixed  in 
each  case  when  using  regenerator  furnaces. 

Best  materials  only  should  be  used  in  such  settings. 

Areas  of  openings  for  introduction  of  primary  and  secondary  air 
and  gas  ducts  vary  considerably,  and  should  all  be  made  so  that  they 
can  be  altered  as  required  by  a  sliding  brick  or  tile. 

Only  a  comparatively  low  temperature  is  required  to  convert  fuel 
to  CO,  and  thus  the  admission  of  cold  air  under  the  furnace  bars 
enables  the  furnace  to  last  long,  owing  to  less  wear  and  tear,  and 
prevents  the  formation  of  clinker,  ash  only  being  found  between 
the  bars. 

In  regenerator  furnaces  the  gases,  before  combustion,  should  be  of 
uniform  quality  and  temperature,  and  should  then  be  directed  into 
and  distributed  over  all  the  interior  of  the  setting. 

The  arrangement  should  be  such  that  combustion  shall  not  be 
complete  until  just  before  the  burnt  gases  are  leaving  the  setting  and 
are  about  to  enter  the  flues  of  the  regenerator. 

The  limit  of  heat  which  may  be  employed  in  a  setting  is  the  fusible 
point  of  the  brickwork  in  the  hottest  part,  and  the  producing  power 
of  the  setting  is  governed  by  the  temperature  of  its  coldest  part. 

It  is  impossible  to  introduce  air  into  a  gas-fired  retort  setting  and 
properly  distribute  it  for  combustion,  without  it  becomes  heated  to 
the  necessary  temperature  for  combustion  with  the  primary  gases. 

It  is  only  by  analysis  of  the  gases  that  it  can  be  accurately  ascer- 
tained if  the  primary  and  secondary  air  are  being  used  in  their  proper 
proportions. 

With  ordinary  settings  M.  Euchene  calcnlates  that  12-8  per  cent,  of 
heat  evolved  from  the  coke,  ets.,  is  lost  by  radiation  through  walls,  etc. 


REGENERATIVE   SETTINGS.  241 

Secondary  air  should  be  heated  to  about  1.800°  F. 
One  third  the  heat  generated  by  the  combustion  of  fuel  is  made 
when  CO  has  been  formed,  the  balance  being  generated  when  this 
is  converted  into  C02 

Saving  in  fuel  with  generator  settings  =  about  25  per  cent. 

,,        „      ,,      „     regenerator    „       =     „      50        „ 
Theoretically  1,100°  F.  are  required  in  the  producer. 
Practically      1,800°  F.    „         „  „  „ 

Composition  of  producer  gases  by  volume. 

Ideal.  Actual. 

CO          ....    34-7  per  cent.    25-7  per  cent. 

CH4 2-75      „ 

H 65-3  per  cent.     14-06     „ 

N 52-74      „ 

C02 4-75      „ 

Temperature  at  combustion  chamber        .  2,600°  F. 

.,  „    crown  of  setting       .         .  2,400°  F. 

„  „    entrance  to  regenerators  2,150°  F. 

„  ,.    outlet  of  last  waste  gas  flue  1,000°  F. 

The  smaller  the  percentage  of  ash  in  the  coke  used  for  regenerative 
firing  the  better,  but,  if  porous,  10  per  cent,  of  ash  can  give  good 
results. 

A  vacuum  of  three-fifths  is  sufficient  at  outlet  of  last  waste  gas  flue. 

Analysis  of  gas  at  last  waste  gas  flue  : — 

CO      .         .         .0-710         .         .         .0 
C02         .        .     .  16-6      |N.         .         .     .  83-3 

Of  each  1  Ib.  coke  placed  in  regenerator  furnaces, 

18    per  cent,  is  ash, 
78f        „          „   carbon, 
3*          „          „   H. 

Of  the  carbon  90  per  cent,  is  converted  to  CO  and  requires  for 
complete  combustion  about  -45  Ibs.  O. 

For  the  hydrogen  about  -26  Ibs.  0  is  required,  or  a  total  of  -71  Ibs.  O 
equal  to  3-l  Ibs.  of  ordinary  air  to  be  raised,  say  1,800°  F. 

Specific  heat  of  air  =  0-2374,  therefore  3-1  Ibs.  x  0'2374  x  1800 
=  1324-7  units  of  heat. 

There  is  always  a  considerable  loss  of  heat  through  the  N.  passing 
away  hot  into  the  air. 

No  gain  of  energy  with  gaseous  fuel,  but  rather  a  loss.  The 
advantages  being  that  the  absolute  conversion  into  CO2  can  be  made 
to  take  place  at  any  or  several  desired  points,  which  might  be 
impossible  to  reach  by  means  of  direct  firing,  and,  again,  the  loss  of 
heat  which  is  radiated  from  the  furnace  in  a  direct  fired  oven  is  not 
so  great,  as  the  intensest  heat  is  only  obtained  at  the  point  where  the 
heat  is  required. 

O.E.  E 


242 

Heat  in  recuperators  should  not  be  more  than  a  dull  red  below  the 
secondary  air  inlet,  as  this  will  probably  mean  too  little  secondary 
air  being  used. 

No  blue  flame  should  be  visible  at  outlet  of  flue,  as  this  shows 
unconsumed  CO. 

About  one-third  the  total  heat  evolved  by  the  fuel  is  used  in 
transforming  the  solid  into  gaseous  fuel. 

Producer  gas  in  Siemen's  furnace  with  coal  containing  70  per  cent, 
fixed  carbon,  16  per  cent,  of  coal  gas,  14  per  cent,  ash  oxygen  and 
nitrogen  (coal  equals  about  7,200  calories).  Producer  gas  consists  by 
weight  of  16  parts  coal  gas,  163*3  of  CO,  and  222  of  N. 

Coal  gas  =  10,000  calories,  CO  =2,400  calories,  then  the  total 
calories  =  551,920  against  700,000  for  the  coal  proper.  (Sir  J. 
Lowthian  Bell.) 

2  to  3  per  cent.  C02  in  generator  gases  shows  very  good  working. 
5  to  6        „  „  „  „  fair  „ 

10  .,  „  „  „  defective         „ 

(W.  Thorner.) 

Wide  furnaces  prevent  the  fire  burning  too  low. 

There  should  be  no  exhaust  on  furnace  except  when  drawing  up 
the  heats. 

Less  air  is  required  with  a  light  than  a  heavy  coke. 

Ordinary  furnaces  allow  a  large  proportion  of  the  CO  to  escape 
without  being  oxidized  to  C02. 

About  25  per  cent,  of  the  heat  evolved  in  an  ordinary  furnace 
passes  up  the  chimney,  of  which  only  one-fourth  is  required  for  the 
necessary  draught. 

Breeze  consists  of  much  earthy  matter,  and  but  little  carbon,  which 
makes  it  a  weak  fuel,  and  much  scoriae  is  deposited  when  burning  it. 

Briquettes  are  made  on  the  Continent  to  burn  coke  dust  and  tar  or 
pitch  for  heating  the  furnaces.  Tar  and  coke  dust  are  sometimes 
mixed  on  the  retort  house  floor  and  then  used  as  fuel. 

Briquettes  are  also  made  by  hydraulic  pressure,  the  proportions 
being  10  per  cent.  pijch  to  the  quantity  of  breeze. 

Clegg  stated  that  when  tar  was  less  than  3d.  per  gallon  it  paid  to 
burn  it  in  the  furnaces,  at  present  it  only  pays  to  burn  when  less 
than  f  d. 

Advantage  of  tar  firing  is  the  slow  and  even  rate  of  supply  as 
compared  with  coke  firing,  by  which  the  necessary  air  supply  is  much 
lessened,  and  the  consequent  cooling  effect  of  the  inert  gases  is  not 
so  great. 

The  superiority  of  liquid  fuel  over  solid  is  principally  due  to  the  H 
contained  in  it,  H  evolving  five  times  the  heat,  weight  for  weight 
that  carbon  does  on  combustion. 

The  use  of  steam  does  not  appear  to  have  any  beneficial  effect 
when  employed  to  inject  tar  into  retort  furnaces  ;  it  has  been  shown 
by  Mr.  Dexter  that  no  increased  heat  can  possibly  result  by  its  use, 
but  that  rather  does  it  tend  to  lower  the  heats. 

Twenty  gallons  tar  required  to  carbonize  1  ton  coal  equals  about  6 
gallons  tar  per  3  bushels  coke. 


REGENERATIVE    SETTINGS.  243 

Provide  a  good  quantity  of  water  in  the  ash  pans  as  the  steam 
prevents  the  formation  of  clinker,  and  prevents  the  over-heating 
of  the  fire-bars. 

It  is  a  moot  point  if  the  water  gas  made  from  the  evaporation  in 
the  ash  pans  is  an  advantage  or  not,  the  amount  of  heat  absorbed  in 
converting  water  to  0  and  H  being  very  great,  but  being  taken  from 
the  lower  layers  of  the  furnace  it  does  not  materially  affect  the  heat 
of  the  bulk  of  the  fuel,  while  the  gain  from  the  burning  of  the 
hydrogen  is  considerable. 

A  jet  of  steam  is  of  assistance  under  the  bars  of  generator  settings. 

The  steam  from  the  ash  pans  is  converted  into  CO  and  H  in 
passing  through  the  red-hot  fuel  in  the  furnace. 

Quantity  of  water  evaporated  per  furnace  per  hour  equals  about  3 
gallons. 

Steam  required  for  producer  equals  about  32  Ibs.  per  100  Ibs.  C 
consumed  or  3-70  Ibs.  water  per  100  Ibs.  coal  carbonized. 

Clinkering  is  reduced  about  one-third  in  regenerator  settings. 

Clinkering  should  be  done  often  enough  to  prevent  such  an 
accumulation  as  will  stop  the  air- way  between  the  fire-bars. 

Clinker  is  due  to  the  combination,  under  the  influence  of  heat,  of 
the  inorganic,  or  incombustible  matter  of  the  coke  (the  ash  of  the 
coal).  This  consists  principally  of  silica,  alumina,  lime,  iron,  &c., 
which  fuses  together  to  form  a  kind  of  slag.  (Hornby.) 

Furnaces  require  repair  about  every  six  months. 

Average  life  of  clay  retort  900  working  days. 

Clay  retorts  will  carbonize  about  4,000,000  cubic  feet. 

Iron  retorts  about  650,000  cubic  feet  of  gas,  and  they  are  done. 

The  broken  surface  of  a  brick  is  much  sooner  acted  on  by  heat 
than  is  the  smooth  face  which  has  a  protecting  skin  upon  it.  Lumps 
are  therefore  to  be  preferred  where  possible. 

The  saving  due  to  the  producer  may  be  taken  at    52-26  per  cent. 
„  „  regenerator        „  „    47-74       „ 

100-00 


If  a  blue  flame  is  seen  at  outlet  of  chimney  of  regenerative  retort 
settings  CO  is  being  passed  away,  and  more  secondary  air  should  be 
let  in. 

Generator  gas  should  consist  of  34'7  per  cent.  CO  and  65-3  per 
cent.  N. 

Chimney  gases  should  contain  21  per  cent.  C02,  1  per  cent.  O 
and  78  per  cent.  N. 

Air  rapidly  absorbs  heat,  and  when  passed  over  heated  surfaces  it 
becomes  raised  in  temperature  approximating  closely  to  that  of  its 
surroundings. 

The  waste  gases  in  a  regenerator  setting  have  been  known  to  be 
reduced  in  temperature  from  1,200°  F.  to  500°  to  600°  F.  by  the 
incoming  of  the  secondary  air,  all  of  which  heat  is  being  saved  and 
used  again  in  the  furnaces. 

B2 


244  GAS  ENGINEER'S  POCKET-BOOK. 

1  lb.  C  converted  to  C02  yields  14,544  heat  units. 

About  double  the  necessary  air  required  in  a  direct  fired  fur- 
nace. 

By  the  higher  heats  of  regenerative  furnaces  Mr.  Foulis  increased 
the  producing  power  of  the  works  60  per  cent. 

One-half  per  cent,  of  free  0  in  the  waste  gases  may  be  considered 
good  working. 

The  depth  of  fuel  should  be  kept  as  regular  as  possible. 

The  use  of  tar  as  fuel  causes  difficulty  in  controlling  furnaces,  and 
regular  and  complete  combustion. 

The  loss  of  gas  from  clay  retorts  in  good  working  order  is  not  at 
all  important.  (L.  T.  Wright.) 

However  hot  the  retort,  an  immediate  and  heavy  fall  in  temperature 
must  follow  the  introduction  of  the  charge,  to  be  worked  up  again  to 
its  maximum  in  the  allotted  period.  (A.  F.  Browne.) 

4  per  cent,  air  reduces  the  illuminating  power  25  per  cent. 

1  per  cent,  of  common  air  diminishes  the  illuminating  power  6  per 
cent. 

45  per  cent,  of  air  renders  the  gas  non-illuminative. 

1-inch  back-pressure  in  retorts  equals  l-24th  candle  power  lost. 

The  sulphur  compounds  are  decomposed  at  a  temperature  of  about 
400°  F. 

In  gas  from  wet  coals  the  olefiant  gas  is  reduced  one-third. 

Crude  gas  contains  4  per  cent,  by  volume  of  gaseous  impurities 
(H2S  and  C02  gas). 

About  1  per  cent,  by  volume  of  the  crude  gas  is  ammoniacal 

About  3  per  cent,  by  volume  of  the  crude  gas  is  C02. 

About  1J  per  cent,  by  volume  of  the  crude  gas  is  H2S. 

Luting  generally  made  of  2  parts  clay  to  1  part  spent  lime. 

If  the  coke  were  drawn  immediately  it  became  incandescent,  say 
about  half-an-hour  before  the  charge  was  done,  much  of  the  trouble 
with  the  sulphur  compounds  would  be  avoided, 

High;  heats  give  a.harder  coke  generally. 

Gas  coke  contains  C,  N,  S,  H,  and  0. 

Coke  contains  about  88  per  cent,  carbon. 

Coke  when  drawn  from  the  retort  and  slaked  contains  about  25  per 
cent,  moisture. 

Coke  averages  1,360  Ibs.  per  ton  of  coal,  with  about  4  per  cent, 
ash  in  the  coke.  About  34  gallons  water  required  to  quench  1  ton 
coke,  of  which  not  more  than  671bs.  water  remains  permanently  in 
the  coke. 

If  steam  be  introduced  along  with  the  air  into  a  coke-making 
plant,  a  larger  percentage  of  ammonia  can  be  extracted. 

59  Ibs.  slack  coal  required  in  furnaces  to  carbonize  2  cwt.  coal. 

41  Ibs.  lump  coal  required  in  furnaces  to  carbonize  2  cwt.  coal, 
say  570  Ibs.  coal  per  ton. 

In  the  petroleum-heated  locomotives  on  the  Great  Eastern  Railway, 
a  thiti  coal  fire  6  inches  thick  (an  ordinary  one  being  18  to  24  inches), 
mixed  with  lumps  of  chalk  to  keep  the  bars  covered,  is  used  so  as  to 
keep  sufficient  heat  up,  when  stopping,  to  re-light  the  oil  when 
re-starting. 

NH8  in  ascension  pipes,  say  560  grains  per  100  cubic  feet, 


LABOUR  REQUIRED  TO  CARBONIZE. 


245 


Men  Employed  in  Making  say  3,000,000  Cubic  Feet  per  Diem 
(Hand  Charging). 


s.  d. 


Retort  house  work  only,  17  (first-class)  men,  made  up 
of  firemen  and  scoop  drivers  ....        at 

1  Foreman 

20  (second-class)  Men  (stokers) 

10  (third-class)  Men  (fire-rakers)  .         ... 

7  Coal  trimmers 

1  Pipe  cleaner 

1  Scurfer    

1  Flue  cleaner        ....... 

1  Lobby  boy 

1  Fitter  .        .        .        . 


The  above  represents  the  number  of  men  employed  on  each  shift  of 
eight  hours.— (January  13th,  1893.) 

Total  Number  of  Men  Required  to  Charge  240  Retorts  with  240  Tons 
of  Coal  per  Diem  at  Glasgow,  Working  8-hour  Shifts. 

(A.  Wilson.) 


Manual  Labour. 

Machine  Work. 

60  Stokers 

6  Charging  machine  men 

15  Firemen 

6  Drawing  machine  men 

15  Ashmen 

15  Firemen 

30  Coalbreakers 

15  Ashmen 

10  Bogie  drivers 

10  Coke  men 

10  Coke  men 

6  Pipe  cleaners 

3  Waterboys 

1  Lid  cleaner 

3  Foremen 

6  Lid  men 

146  men. 

3  Coal  breaker  men 



3  Locomotive  boys 

Also  7  horses  to  draw  out  the 
coke. 

3  Shunters 
3  Foremen 

77  men. 

Number  of  Men  Employed  on  Furnaces  (during  8  hours). 

li  firemen  clean  2  fires  and  fill  4. 

4  firemen  in  24  hours  attend  4  fires  (cleaned  every  6  hours). 
1  fireman   attends   the  equivalent  of  6 '01  fires  (on  the  ordinary 
open  double  grate  system). 

Number  of  men  employed  on  furnaces  (during  8  hours)  of  15  sets. 
"  Buffalo  Bill  "  settings  (1  furnace  to  five  sets). 
"2\  firemen  clean  4  fires  and  feed  from  the  top  every  2  hours. 
1\  firemen  in  24  hours  attend  3  fires  (fires  cleaned  every  6  hours). 


246  GAS  ENGINEER'S  POCKET-BOOK. 

1  fireman  attends  the  equivalent  of  12  fires  (on  the  ordinary  open 
double-grate  system). 

Each  stoker  may  be  made  to  handle  an  average  of  4  ton  coal  per 
day. 

Charging  should  be  performed  in  rather  less  that  one  minute. 

The  air  compressor  at  the  South  Metropolitan  Gasworks  used 
with  the  "West  stoking  machinery,  shows  a  high  duty,  the  mechanical 
efficiency  is  80*3  per  cent.,  the  compression  efficiency  is  82*1  per  cent., 
and  the  air  delivery  equals  369*3  cubic  feet  per  I.H.P.  per  hour. 

To  Prevent  Stopped  Pipes  they  should  be  kept  cool,  and  light  seals 
in  the  hydraulic  maintained  in  liquor  and  not  tar. 

Space  between  ascension  pipes  and  front  wall  of  bench  should  not 
be  less  than  8  inches. 

Water  may  be  introduced  at  the  top  of  the  ascension  pipe  and 
allowed  to  trickle  down  the  sides  of  the  pipe. 

Stopped  pipes  sometimes  attributed  to  oscillation  and  pressure  in 
the  retorts  from  the  dip  and  the  exhauster. 

Thick  tar  and  soot  and  stopped  ascension  pipes  are  sometimes 
caused  by  porous  parts  in  retorts,  either  new  or  recently  cleared  from 
carbon,  which  allow  the  gas  to  pass  through  and  burn  in  the  setting, 
while  the  soot  and  tar  are  carried  up  and  deposited  in  the  ascension 
pipe  and  hydraulic.  The  obvious  cure  is  to  paint  the  inside  of  the 
retort  after  such  clearing  of  carbon  and  when  new,  with  thin  fire- 
clay mortar,  and  thus  close  the  pores. 


Suggestions  for  the  Curing  of  Stopped  Ascension  Pipes. 

Allow  water  to  trickle  down  the  interior  from  the  top. 

Place  a  bowl  of  water,  or  rag,  or  waste  soaked  in  oil,  small  coal 
soaked  in  water,  or  pieces  of  solid  grease,  inside  the  retort,  just  below 
the  bottom  of  the  ascension  pipe. 

Keep  open  all  doors,  windows,  or  other  available  apertures. 

Bring  a  supply  of  cold  air,  from  outside,  to  the  front  of  the  bench  by 
means  of  pipes. 

Keep  the  retorts  charged  to  their  utmost  capacity. 

Lower  the  heats  of  the  retorts  ;  this  also  clears  the  hydraulic  by 
causing  oily  tar  to  pass  off  from  the  coal. 

Loss  from  stopped  pipes  has  been  known  to  exceed  10  per  cent,  of 
the  gas  to  be  obtained  from  the  coal. 

Stopped  ascension  pipes  usually  caused  through  excessive  heat 
from  setting. — To  diminish  the  trouble,  walls  in  front  of  benches 
should  be  14  inches  and  not  9  inches  thick. 

Rapid  radiation  of  heat  and  smooth  interior  surface,  said  to  obviate 
stopped  pipes. 

To  prevent  stopped  ascension  pipes,  leave  the  retort  mouthpiece  and 
the  pipe  open  to  the  air. 

The  temperature  of  the  pipes  must  be  moderated  by  a  supply  of 
water  which  is  led  into  them  by  a  U-shaped  tube  screwed  into  their 
upper  ends.  The  water  drips  into  this  tube  from  a  supply  above  it. 
03  to  70  ounces  water  per  retort  per  hour  required. 


EFFECTS    OF    HEAT. 


247 


The  gas  in  the  ascension  pipes  is  usually  of  a  temperature  of  about 
200»  F. 

Air  circulating  round  the  pipes  and  mouthpieces. 

Water  supplied  internally  or  externally. 

Liquor  supplied  internally  or  externally. 

A  lump  of  coal  in  the  mouthpiece. 

A  handful  of  oily  waste  in  the  mouthpiece. 

Animal  fat  in  the  mouthpiece. 

Increase  in  length  of  rising  pipe. 

Plate  or  plates  inside  mouthpieces  to  prevent  radiation  of  heat 
from  inside  retort. 

Lining  mouthpiece  with  fire-clay. 

Air  or  water  jacket  to  ascension  pipe. 

Carbon  deposited  in  the  retorts  is  generally  increased  by  increase 
of  pressure. 

An  oscillation  caused  by  a  badly  working  exhauster  causes  a 
greater  deposit  of  carbon  than  a  steady  exhaust. 

Pressure  and  oscillation  are  the  chief  causes  of  deposition  of  carbon. 

The  pressure  on  retorts  is  sometimes  as  high  as  15  inches  water 
where  an  exhauster  is  not  in  use  and  the  carbon  deposit  is  then 
considerable. 

The  carbon  deposited  in  the  retorts  consists  of  the  richest  illu- 
minants  of  the  gas  which  have  been  solidified  instead  of  carried 
forward  in  the  gas. 

If  there  be  a  heavy  pressure  in  retorts  some  of  the  hydrocarbons 
are  deposited  as  carbon  in  the  retorts. 

Under  pressure  some  of  the  most  valuable  hydrocarbons  are 
deposited  in  the  retort  as  carbon  or  scurf. 

The  removal  of  the  carbon  from  sloping  retorts  is  easy,  as  the 
position  of  the  latter  causes  a  current  of  cool  air  to  pass  up  when 
both  doors  are  opened. 

Carbon  or  scurf  is  removed  by  a  chisel  bar,  or  by  allowing  the 
oxygen  of  the  air  to  burn  the  deposit  until  it  is  thin  enough  to 
remove  easily ;  this  should  be  done  about  once  a  month. 

The  carbon  in  a  retort  being  highly  non-conducting,  causes  con- 
siderable waste  of  fuel,  and  should  therefore  never  be  allowed  to  get 
very  thick. 

Clay  retorts  are  practically  gas-tight  up  to  about  J-inch  pressure. 

To  prevent  carbon  deposits,  reduce  the  dip  and  the  back  pressure 
as  much  as  possible. 


Table  of  the  Effects  of  Heat. 


Soft  iron  melts 
Cast  iron  melts     . 
Gold  melts 
Copper  melts 
Silver      „ 

Bronze     .,      (copper 
parts,  tin  1  part) 


16 


Degrees. 
Fahr. 
.  3,945 
.  2,786 
,  2,016 
.  1,996 
1,873 

1,750 


Degrees 
Fahr. 
Brass  melts  (copper  3  parts, 

zinc  1  part)  .        .        .    1,690 
Brass  melts  (copper  2  parts, 

zinc  2  parts)     .        .     .     1,672 
Diamond  burns         .        .     1,552 
Bronze    melts   (copper  7 
parts,  tin  1  part)      .    .     1,534 


248 


GAS  ENGINEER'S  POCKET-BOOK. 


Table  of  the  Effects  of  Heat — continued. 


Degrees. 

Degrees. 

Fahr. 

Fahr. 

Bronze   melts    (copper  3 

Steel  becomes  a  full  yellow 

470 

parts,  tin  1  part)  . 

1,446 

Steel  becomes  a  pale  straw 

Enamel  colours  burn    .     . 

1,392 

colour        .        .        .     . 

450 

Iron  red  hot  in  daylight  . 

1,272 

Tin  melts  . 

442 

Iron  red  hot  in  twilight   . 

884 

Steel  becomes  a  very  faint 

Iron  red  hot  in  dark 

800 

yellow       .        .        .     . 

430 

Charcoal  burns    .         .     . 

802 

Tin  3  +  lead  2  +  bismuth 

Heat  of  a  common  fire 

790 

1  melts 

334 

Zinc  melts    .        .        .     . 

773 

Tin  and    bismuth,   equal 

Mercury  boils  . 

660 

parts,  melts      .        .     . 

283 

Linseed  oil  boils  .        .     . 

640 

Sulphur  melts  . 

218 

Lowest  ignition  of  iron  in 

Bismuth  5  +  tin  3  +  lead 

the  dark 

635 

2  melts                       .    . 

212 

Lead  melts  .         ... 

612 

Water  boils 

212 

Steel  becomes  dark  blue, 

Wax  melts    .        .        .     . 

149 

verging  on  black  . 

600 

Tallow  melts     . 

92 

Steel  becomes  a  full  blue  . 

560 

Acetic  acid  congeals    .     . 

50 

Sulphur  burns  . 

560 

Olive  oil  congeals     . 

36 

Steel  becomes  blue      .    . 

550 

Water  freezes       .        .     . 

32 

Steel  becomes  purple 

530 

Milk  freezes 

30 

Steel  becomes  brown,  with 

Vinegar  freezes    .        .     . 

28 

purple  spots     .        .    . 
Steel  becomes  brown 

510 
490 

Sea  water  freezes 
Strong  wine  freezes      .     . 

28 
20 

Bismuth  melts     .        .    . 

476 

Turpentine  freezes   . 

14 

Colours  of  Different  Temperatures.    (Becquerel.) 

I 

)egrees. 

Degrees. 

Fahr. 

Fahr. 

Faint  red 

960 

White  heat.        .        .     . 

2,370 

Dull  red       .... 

1,290 

Bright  white  heat    . 

2,550 

Brilliant  red     .         .        . 

1,470 

Brilliant  white  heat    .     . 

2,730 

Cherry  red   .        .        .     . 

1,650 

Melting  point  of  cast  iron 

2,786 

Bright  cherry  red 

1,830 

Welding  heat      .         .     . 

2,800 

Orange          .        .        .     . 

2,010 

Greatest  heat  of  iron  blast 

Bright  orange  . 

2,190 

furnaces 

3,300 

600°  F.  Faint  red  in  dark  room. 
662°  F.  Mercury  boils. 
810°  F.  Antimony  melts. 
1,869°  F.  Brass  melts. 


1,873°  F.  Silver  melts. 
1,996°  F.  Copper  melts. 
2,786°  F.  Cast  Iron  melts. 


Temperature  of  iron  when  red  glow  has  disappeared,  404°  C. 
It  is  said  that  no  reliability  can  be  placed  on  Wedgewood's  pyro- 
meter. 


PYROMETERS.  249 

Pyrometers. 

One  part  of  zinc  and  4  parts  of  copper  melts  at  1,050°  C.  ; 
1  part  of  zinc  and  6  parts  of  copper  melts  at  1,130°  C.  ;  1  part 
of  zinc  and  8  parts  of  copper,  at  1,160°  C.  ;  1  part  of  zinc  and  12 
parts  of  copper,  at  1,230°  C.  ;  and  1  part  of  zinc  and  20  parts  of 
copper,  at  1,300°  C.  The  difficulty  of  getting  pure  metals  to  make 
these  alloys,  and  of  keeping  them  at  the  initial  proportion,  is  against 
their  use.  The  expansion  of  metals,  clays,  liquids  and  gases  under 
heat  is  also  used  with  varying  success.  The  Lamy  pyrometer,  based 
on  the  decomposition  of  carbonate  of  lime  under  heat,  is  one  of  the 
best  ;  but  it  will  only  register  between  700°  and  900°  C. 

Herr  C.  Schneider  proposes  the  use  of  nitrifiable  test  cones,  con- 
taining silica  65  per  cent.,  alumina  8'3  per  cent.,  ferric  oxide  8'7 
per  cent.,  lime  10*6  per  cent.,  and  potash  7'6  per  cent.,  or  in  vary- 
ing proportions,  to  test  the  heat  of  chambers  with  heats  from 
1,150°  C.  to  1,700°  C.  The  greater  the  quantity  of  silica  the  more 
refractory  the  cone,  the  above  mixture  melting  at  1,150°  C.  ;  and  by 
the  substitution  of  8  per  cent,  of  boracic  acid  for  the  equivalent  of 
silica  the  melting  point  equals  960°  C.  Or  crystallized  borax  193  parts, 
marble  50  parts,  china  clay  52  parts,  sand  96  parts,  will  melt  at  960°  C. 

Seger's  standard  fusible  cones  are  used  to  determine  the  tempera- 
tures at  which  fusion  occurs.  These  cones  are  tetrahedra,  compounded 
of  mixtures  of  clay  and  sand  with  certain  fluxes.  For  temperatures 
from  1,300°  to  1,700°  F.,  soda  and  lead  oxide  form  the  flux  ;  while 
boric  acid  is  used  for  temperatures  from  1,700°  to  2,050°  F.  The  same 
flux  is  used  with  gradually  increasing  proportions  of  alumina  and 
silica  up  to  3,450°  F.  The  last  cones  of  the  series,  which  are  stated 
to  fuse  at  temperatures  from  3,500°  to  3,950°  F.,  consist  of  pure 
aluminium  silicate. 

Mr.  P.  Mahler's  calorimeter  consists  of  a  shell  or  hollow  cylindrical 
vessel,  enclosed  in  another  containing  water  at  a  known  temperature. 
The  shell  being  hermetically  closed,  pure  oxygen,  at  a  pressure  of 
several  atmospheres,  is  admitted,  and  the  fuel  fired  by  an  electric 
spark,  when  the  pressure  of  the  compressed  oxygen  causes  complete 
and  almost  instantaneous  combustion.  The  heat  generated  is  trans- 
mitted to  the  water  surrounding  the  shell,  the  temperature  of  which 
rises  immediately.  Mr.  Mahler  uses  only  one  grain  of  combustible. 
When  gas  is  tested  a  vacuum  must  be  produced  in  the  shell  before 
gas  is  admitted,  and  the  quantity  of  oxygen  necessary  for  com- 
bustion previously  determined.  Illuminating  gas  ignites  with  oxygen 
at  a  pressure  of  five  atmospheres,  producer  gas  requires  a  pressure  of 
about  half  an  atmosphere  in  the  oxygen. 

To  find  temperature  of  a  furnace — weigh  a  piece  of  metal,  place 
in  furnace,  withdraw  when  heated  and  immerse  in  a  known  weight 
of  water 

Then  Tl-w*<%-™  +  Tt  where 

Tj  =  temp,  of  metal  before  immersion  w  =  weight  of  water 

T-2  =      ,j          water      „  „  S  =  specific  heat  of  pyrometer 

Ta=      „  „     after  „  s  =        „         „       water  (=1) 

W  =  weight  of  metal. 


250 


GAS  ENGINEER'S  POCKET-BOOK. 


Tallow  . 
Spermaceti 
Wax,  white 
Sulphur 
Tin 

Bismuth     . 
Lead      . 
Zinc  . 


Temperature  of  Fusion. 

Degrees. 

Degrees. 

Fahr. 

Fahr. 

.       92 

Antimony    . 

810 

.     120 

Brass       .         .     . 

1,650 

.     154 

Silver,  pure. 

1,830 

.     239 

Gold,  coin       .     . 

2,156 

.     455 

Iron,cast,medium 

2,010 

.     518 

Steel       .        .     . 

2,550 

.     630 

Wrought  iron 

2,910 

.     793 

Melting  Points  of  Fusible  Alloys. 


Tin. 

Lead. 

Bis- 
inuth. 

Degrees. 
Fahr. 

Tin. 

Lead. 

Bis- 
muth. 

Degrees. 
Fahr. 

2 

3 

5 

199 

8 

15 



430 

1 

1 

4 

201 

1 

2 



440 

3 

2 

5 

212 

8 

17 



450 

4 

1 

5 

246 

4 

10 



470 

1 

1 

1 

255 

1 

3 



480 

2 

2 

1 

292 

4 

14 



490 

3 

3 

1 

310 

8 

33 



500 

4 

4 

1 

320 

1 

5 



510 

H 

1 

— 

330 

4 

25 



520 

2' 

1 

— 

340 

4 

30 



530 

4 

1 

— 

365 

1 

10 



540 

1 

1 



370 

1 

12 



550 

6 

1 

— 

380 

1 

25 



560 

4 

7 

— 

420 

An  average  sample  of  coal  gives  the  following  figures  :— 

Carbon  (C) 82*12  per  cent. 

Hydrogen  (H) 5-31       „ 

Nitrogen  (N) 1-35       „ 

Sulphur  (S) 1-24        „ 

Oxygen  (0) 5'69       ,, 

Ash    .  4-29       ,. 


(Lancet.) 


Percentage  of  coal  in  its  use  : — 


10,000  cubic  feet  gas  =  17    per  cent. 
10  gallons  tar  =    5'1      ., 

Condensed  liquor       =    7-9     „ 
•Coke  =  70       „ 

(Professor  Lewes,  1894.) 


RESIDUALS    FROM   COAL.  251 


Approximate  composition  of  bituminous  coal : — 

C    80-0  per  cent.  N     1-5  per  cent. 

H      5-0       „  0     5-0       „ 

S       1-5       „  Ash  3-0 

Moisture  4-0  per  cent.  Calorific  value  8,020  thermal  units. — 
(Professor  Lewes.) 

Cannel  coal -specific  gravity  1-1  to  1-4,  organic  matter  consists  of 
C  =  70  to  85  per  cent.  ;  0  =  5  to  15  per  cent.  ;  H  =  5*5  to  lO'O  per 
cent.  ;  N  =  1  to  2 '5  per  cent.  ;  S  =  0'5  to  2 '5  per  cent.  ;  Ash  5  to 
20  per  cent. 

Ash  from  average  Newcastle  coals  .-  — 

Silica 60 

Peroxide  of  iron 16 

Alumina 12 

Lime 10 

Potash 1 

Magnesia 1 

2  to  4  gallons  of  water  per  ton  is  the  average  moisture  in  mechanic.il 
combination. 

Laboratory  tests  of  coals  are  generally  15  to  20  per  cent,  higher 
than  actual  working  results. 

About  16  gallons  of  water  are  produced  by  carbonizing  1  ton  coals. 
Gas  made  per  ton  Gas  Light  &  Coke  Co  \  year  to  December,  1892, 
10,949  cubic  feet. 

Coke  made  '617  ton  per  ton. 
Breeze  „     '064    „ 

C02  in  crude  gas        .        .        .        .     2' 5  to  3  per  cent. 
H2S     „        „ 1  to  2       „ 

CS3  is  formed  by  the  action  of  sulphur  vapour  upon  red  hot  carbon. 

Tar  can  be  carbonized  in  ordinary  clay  retorts  if  allowed  to -run 
into  the  ascension  pipe  on  to  a  fire  clay  tile  fitted  in  the  mouthpiece 
to  prevent  any  accumulation  of  tar  behind  the  lids,  40  gallons  being 
burnt  off  in  6  hours.  Iron  retorts  are  however  better.  Tar  conduit 
pipes  should  be  large,  say  2-inch. 

Paper  becomes  charred  at  400°  P. 

Table  showing  conversion  of  the  elements  of  coal  on  carbonization 

=  CH4  &  C2H4  etc. 


N 


J  35-26  free-in  gas  and 
|  in  tar,  48*68  in  coke. 


252 


GAS   ENGINEER  S    POCKET-BOOK. 


A  good  gas  coal  should  contain  as  large  a  percentage  of  H  over 
and  above  that  required  to  combine  with  the  0  as  possible,  and  this 
should  not  be  less  than  4  per  cent.,  while  5  per  cent,  will  show  a 
high  quality  coal.  To  obtain  the  quantity  of  H  Avhich  will  oxidize 
on  carbonization  divide  the  percentage  of  O  by  8  and  deduct  the 
dividend  from  the  percentage  of  H. 

Total  quantity  of  carbon  in  coal  =  82  per  cent. 
Gas  contains  „  „     =  16       „ 

Coke  and  tar  „          „    =  66       „ 

Caking  coal  has  specific  gravity  1*25  to  T35,  and  the  organic 
matter  in  it  consists  of  80  to  90  per  cent.  C,  4-5  to  6  '0  per  cent. 
H,  5  to  13  per  cent.  0,  and  1  to  2-5  per  cent.  N,  average  ash  7*5  per 
cent.,  sulphur  0'5  to  2'5  per  cent.  (Butterfield.) 


Lancashire 
Coal. 

Newcastle 
Coal. 

Welsh 
Coal. 

Scotch 
Coal. 

C     per  cent. 

80-70 

83'60 

86-26 

78-50 

H 

5-50 

5-28 

4-66 

8-33 

o 

8-48 

4-65 

2-60 

8.33 

N 

1-12 

1-22 

1-45 

1-14 

S 

1-50 

1-25 

1-77 

1-45 

Ash 

2-70 

4-00 

3-26 

4-00 

Coal  contains  from  50  to  80  per  cent,  by  weight,  of  carbon. 

Average  composition  80  per  cent.  C,  5  per  cent.  H,  8  per  cent.  0. 
4  per  cent,  ash,  1J  per  cent.  S,  1£  per  cent.  N.  Coke  equals  61  per 
cent.,  specific  gravity  equals  1-279,  weight  per  cubic  foot  equals 
80  Ibs.  Bituminous  coal  contains  from  6  to  10  per  cent,  water. 

In  most  Tars  there  are  40  per  cent,  of  compounds  capable  of 
conversion  into  illuminating  gases. 

An  ordinary  sample  of  tar  will  yield  at  least  16,000  cubic  feet  of 
15  candle  gas  per  ton  of  200  gallons,  with  coke,  free  from  ash,  weigh- 
ing about  10  cwt.,  and  if  produced  at  proper  temperatures  equal  to 
foundry  coke,  ammonia  equal  to  the  production  of  16  Ibs.  sulphate 
per  ton  of  tar. 

The  theory  of  the  tar  process  as  used  at  Widnes  is  that  a  fresh 
charge  of  coal  cools  the  retort  for  a  time,  during  which  a  considerable 
quantity  of  tarry  vapours  are  being  given  off  from  the  coals,  and 
these  tarry  vapours  are  carried  along  the  duct,  as  the  second  retort  is 
called,  and  there  gasified  into  permanent  gases  instead  of  being 
deposited  in  the  condenser  mains  as  tar. 

The  volume  of  Gas  from  Wood  Charcoal  amounts  to  250  litres  per 
kilogramme,  and,  when  prepared  on  a  large  scale,  it  contains  C02 
9-14  per  cent.,  CO  18-08  per  cent.,  H  49-11  per  cent.,  CH4  16-04  per 
cent.,  O  0-26  per  cent,  N  7-37  per  cent.  (Comptes  Rendus.) 

Wood  Gas  gives  about  8,000  cubic  feet  per  ton  of  poor  gas. 

Mr.  W.  King,  of  Liverpool,  found  that  the  average  yield  per  ton  of 
tar  thoroughly  dried  at  212°  F.  before  carbonization  was  12,000  cubic 


GAS    FKOM    DIFFERENT    SUBSTANCES.  253 

feet  01  4-candle  gas,  5£  cwt.  charcoal  (worthless  for  fuel),  33  per 
cent.  CO,  and  very  little  tar. 

By  the  Dinsmore  process,  following  a  coal  gas  carbonization, 
afcout  10,000  cubic  feet  per  ton  of  19-candle  gas  are  obtained  from  a 
poor  coal. 

One  Ton  Split  Wood  yields  11,000  cubic  feet  per  ton  of  16 
candles,  with  4  cwts.  charcoal,  and  1  to  l£cwts.  of  tar,  with  a  large 
quantity  of  C02  (9  to  18  per  cent.). 

Cork  refuse  made  18,000  cubic  feet  gas  per  ton  of  good  quality  and 
purity.  (N.  H.  Humphrey.) 

Pine  Wood  Sawdust  carbonized  at  1,500°  F.  yields  12,300  to  15,700 
cubic  feet  per  ton  of  dried  material  of  15  candles  (specific  gravity 
•590  to  -620),  and  contains  about  7'5  per  cent,  illuminants,  33  per 
cent.  H,  27  per  cent,  CH4,  32  per  cent.  CO. 

High  heats,  light  charges,  and  plenty  of  red-hot  surface  have  been 
found  best  when  carbonizing  wood  for  gas-making  purposes. 

Peat  perfectly  dried  and  compressed  yields  at  red  heat  11,000  cubic 
feet  per  ton  of  17  to  18  candle  gas  with  9  cwts.  coke,  15  gals,  tar, 
and  a  quantity  of  ammonia.  (Butterfield.) 

Peat,  average  composition  :  Water  16-4,  C  41 -0,  H  4-3,  0  23 '8,  N  2 '6, 
ash  ll'S  ;  sp.  gr.  1-05  ;  gives  8,400  B.  T.  U.'g  per  1  Ib. 

The  tar  should  be  removed  as  Boon  as  its  temperature  is  down  if. 
100°  to  110°  F. 

Gas  washed  with  the  heavier  hydrocarbons,  as  in  a  tar  seal  in  p 
hydraulic  main,  absorbs  a  number  of  the  lighter  hydrocarbons  which 
would  otherwise  remain  in  the  gas  and  give  it  a  higher  illuminating 
power. 

If  too  much  tar  is  allowed  to  remain  in  the  hydraulic  main,  the 
heat  of  the  incoming  gas  gradually  boils  off  the  lighter  oils  and 
causes  the  formation  of  pitch. 

The  gas  which  enters  the  hydraulic  main  from  the  ascension  pipe, 
carries  with  it  a  number  of  hydrocarbon  vapours,  condensing  at  from 
140°  to  160°  F. 

Mr.  L.  T.  Wright  proposed  to  run  in  water  to  keep  the  temperature 
of  the  hydraulic  main  at  about  100°  F.,  and  thereby  reduce  the 
quantity  of  impurities  in  the  gas. 

The  lighter  hydrocarbons  which  condense  at  temperatures  above 
100°  F.,  do  not  injure  the  illuminating  power  of  the  gas,  and  may 
absorb  any  excess  of  napthalene.  (Herring.) 

If  a  hot  liquid  is  used  in  the  hydraulic  mains,  weak  ammoniacal 
liquor  would  be  likely  to  liberate  its  ammonia,  and  increase  the 
amount  of  that  impurity  to  be  removed  later  on. 

Gas  as  it  leaves  the  retorts  is  enveloped  in  very  minute  tarry 
vesicles  which  require  friction  to  break  thtm  up. 

Gas  on  leaving  the  dip-pipe  should  pass  through  water  and  not  tar. 

Liquor  may  be  run  in  to  replace  tar  in  hydraulic  twice  a  day. 

Hydraulic  main  tar  will,  at  130°  F.,  dissolve  upwards  of  70  per  cent, 
of  napthalene,  so  that  it  will  be  seen  what  a  powerful  factor  in  re- 
moving this  is  eliminated  by  using  liquor  seals  in  the  hydraulic  mains. 

The  liquor  in  the  hydraulic  main  consists  of  sulphocyanide  and 
hyposulphate  of  ammonia,  also  some  carbonate  and  sulphide. 


254  GAS  ENGINEER'S  POCKET-BOOK. 

Anti-dip-pipes  should  be  worked  so  that  there  is  a  pressure  in  the 
retorts,  and  then  no  deleterious  gases  are  drawn  in  through  cracks  in 
the  retorts. 

Mr.  Gandon  found  an  increase  of  300  to  400  feet  per  ton  with  anti- 
dip  pipes. 

At  outlet  of  hydraulic  main  -3  to  -5  of  the  condensable  constituents 
are  deposited.  (Professor  Wanklyn.) 

Half  to  one- third  the  condensable  vapours  are  deposited  in  the 
hydraulic  mains. 

Crude  gas  contains  about  143  grains  ammonia  per  100  cubic  feet, 
2-95  per  cent.  H2S.,  2-04  per  cent.  C02. 

In  the  hydraulic  main,  for  every  100  volumes  free  ammonia  there 
are  about  24  volumes  CO2  and  11  volumes  H2S. 


Temperatures  found  in  Ascension  Pipe.     (W.  Foulis.) 

18  Inches  from  12  Feet  from  22  Feet  from 

Mouthpiece.  Mouthpiece.  Mouthpiece. 

890°  to  518°  F.  444°  to  167°  F.  246°  to  144°  F. 

Temperature  in  retort,  18  inches  from  mouthpiece,  1,110°  to  1,040°  F. 

Temperatures  fell  as  above  during  charge,  always  getting  lower  as 
charge  was  worked  off.  Gas  made  equalled  10,000  cubic  feet  per  ton. 

If  only  6,000  cubic  feet  per  ton  were  being  made,  temperature,  at 
18  inches  from  mouthpiece,  in  ascension  pipe  would  probably  be  only 
4  00°  to  500°  F. 

Temperature  of  gas  leaving  hydraulic  main,  50°  to  60°  C.,  or  110°  to 
150°  F. 

Temperature  of  gas  leaving  condenser,  15'5°  C. 

Temperature  of  foul  main  averages  about  110°  F.  to  138°  F. 

Usually  considered,  the  temperature  of  gas  in  leaving  the  retort 
squais  200°  to  300°  F..  but  unless  it  is  as  high  as  480°  F.  thickening 
t)f  the  tar  in  the  hydraulic,  and  choking  of  the  ascension  pipe  will 
certainly  occur. 

The  gas  leaving  a  retort  freely  has  only  a  temperature  of  220°  to 
830°  F.,  owing  to  the  great  absorption  of  heat  on  its  assuming  a  gaseous 
form. 

Temperature  of  gas  3  feet  above  mouthpiece  150°  to  170°  F.;  17 
feet  from  mouthpiece  120°  to  135°  F. 

M.  Euchene  gives  (1900)  chimney  gases,  ordinary  retorts,  1,787°  F. 
Temperature  in  gas  in  retort,  at  first  1,166°  F.,  at  end  of  charge  1,355°  F., 
average  1,260°  F.,  but  as  the  volatile  products  come  off  early,  average 
taken  as  1,202°  F.  Temperature  in  retort  mouthpiece  from  788°  F. 
to  824°  F.  Temperature  in  hydraulic  main  176°  F.  Temperature  in 
charge  in  retort  932°  F.  in  first  half -hour,  rising  to  1,740°  F.  during 
distillation. 


CONDENSING    GAS.  255 


CONDENSING. 

The  Products  of  one  Ton  of  Newcastle  Coal  after  Carbonization 
are: — 

Lbs.  Per  Cent. 

10,000  cubic  feet  of  gas          .         .         380  .         .     17-0 

10  gallons  of  tar        .         .         .     .         115  ...       5-1 

Virgin  gas  liquor  .         .         .         .         177  .         .7-9 

Coke 1,568  .    .    .     70-0 

2,240  100-0 


One  ton  of  coal  yields  5  per  cent,  weight  of  tar  (approximately). 
(Wanklyn.) 

About  8  feet  of  H2S  is  contained  per  1.000  cubic  feet  of  Newcastle 
coal  gas. 

About  25  cubic  feet  of  CO2  is  contained  per  1,000  cubic  feet  of 
Newcastle  coal  gas. 

7  to  12  per  cent.  CO  is  present  in  coal  gas. 

CO  has  a  greater  diluting  effect  than  H. 

H  has  a  greater  diluting  effect  than  marsh  gas. 

10  to  13  gallons  tar.  and  13  to  30  gallons  water  are  deposited  by  the 
time  the  gas  reaches  the  outlet  of  the  condensers. 

The  idea  which  some  engineers  had  of  leaving  the  gas  with  the  tar 
as  long  as  possible  was,  that  they  believed  the  latter  absorbed  C02 
and  H2S,  but  the  quantity  of  rich  hydrocarbons  also  absorbed  was 
not  taken  into  account. 

Doing  away  with  the  condenser  at  Kichmond  practically  raised  the 
illuminating  power  of  the  gas  f  candle.  (T.  May.) 

If  gas  be  condensed  below  45°  F.  the  illuminating  power  is  reduced, 
extreme  cold  having  a  detrimental  effect  on  the  illuminating  power. 

The  tar  should  be  removed  from  the  gas  as  soon  as  possible  until 
the  latter  has  been  cooled  to  about  105°  F. 

If  the  heavy  tar  oils  and  pitch  are  allowed  to  continue  with  the 
gas  which  is  above  90°  F.  they  absorb  hydrocarbons  from  the  gas. 

The  gas  enters  the  condenser  main  at  about  122°  F. 

The  temperature  of  the  gas  should  be  gradually  reduced  to  90°  F. 
before  it  enters  the  condensers. 

Condensation  is  required  to  remove  all  the  tarry  vesicles,  and  if 
this  be  done  the  temperature  of  the  gas  may  be  left  to  take  care  of 
itself  as  it  will  be  cooled  later  on  to  atmospheric  temperature. 

The  condensers  are  best  kept  at  the  normal  temperature  of  the  air. 
If  above  or  below  this,  the  action  of  the  purifier  is  interfered  with. 

Much  inconvenience  in  scrubbers  and  washers  may  be  avoided  by 
arranging  condensers  so  that  the  gas  is  not  cooled  excessively. 

If  the  gas  is  not  properly  condensed  before  it  enters  the  scrubbers 
the  efficiency  of  the  latter  will  be  impaired. 

The  richer  the  gas  the  greater  the  loss  of  hydrocarbons  by  exposure 
to  low  temperature. 


256  GAS  ENGINEER'S  POCKET-BOOK. 

When  the  condensation  is  carried  below  60°  F.,  and  friction  is 
made  to  take  place  napthalene  is  frequently  deposited. 

It  is  better  to  have  napthalene  in  the  works  than  in  the  district. 

Napthalene  deposition  in  the  works  can  be  prevented  by  the  use  of 
liquor  seals  in  place  of  tar,  by  quickly  removing  the  tar  from  contact 
with  the  gas,  and  by  long  condensing  or  foul  mains. 

Keeping  up  the  temperature  at  outlet  of  condensers  to  60°  to  75°  F. 
will  prevent  the  deposition  of  napthalene  at  that  point,  but  may  send 
it  into  the  district. 

It  has  been  suggested  to  keep  the  temperature  of  the  tar  and 
liquor  in  the  hydraulic  main  at  about  100°  F.  so  that  the  tar  may 
retain  a  portion  of  the  napthalene  and  bi-sulphide  of  carbon  which 
it  will  not  do  at  160°  F. 

If  gas  is  thoroughly  dried  no  napthalene  is  deposited. 

One  method  of  clearing  the  napthalene  from  condensers  is  to  run 
a  small  stream  of  liquor  periodically  into  the  first  three  or  four 
compartments. 

Poor  gas  may  tend  to  the  deposition  of  napthalene  as  certain 
hydrocarbons  have  the  power  of  carrying  others  of  different  specific 
gravity. 

A  sudden  cooling  of  the  gas  causes  deposits  of  hydrocarbons  and 
napthalene. 

Napthalene  fuses  at  176°  F.,  boils  at  423°  F.,  is  not  soluble  in 
water. 

To  cure  this  trouble  avoid  wet  coal — keep  your  heats  as  even  as 
possible. 

Tests  for  Napthalene, 

Dilute  ammoniacal  liquor  with  sulphuric  acid,  and  if  napthalene 
be  present  it  becomes  rose  colour  and  smells  of  napthalene. 

Kedden  liquor  with  nitric  acid  super-saturated  with  muriatic  acid. 
If  napthalene  be  present  it  will  tinge  a  piece  of  firwood  a  rich 
purple. 

In  order  to  dissolve  napthalene  in  the  condensers,  Mr.  Carpenter 
arranged  a  condenser  to  be  reversible.  When  the  outlet  became 
partly  choked  it  was  made  the  inlet.  The  tarry  vapours  of  the  hot 
gas  dissolved  the  deposit,  which  was  quickly  run  off  by  the  seals. 

The  liquor  from  the  condensers  contains  sulphocyanide,  sulphate 
and  hyposulphite  among  the  fixed  salts  of  ammonia. 

Analysis  of  Grade  Gas  leaving  Condensers.     (Butterfield.) 

By  Volume.  Per  100  Cubic  Feet. 


NH3      .  .  O'f>5    to  0-95  percent. 

C02  .         .  .  1-2      „  1-8       „       „     , 

H2S      ..  .  0-9      „  1-5       „      „ 

CS2 .          .  .  0-020  „  0-035   „       „    , 

Cyanogen  .  0-05    „  O'lO     „      „ 

Napthalene  .  0-005  „  0-015  „      „ 


200  to    300  grains 
980        1470 


570 
28 
50 
12 


950 
50 

100 
35 


TESTS    OF    GAS   AFTER    CONDENSERS. 


257 


Analysis  of  Crude  Gas  Leaving  Condensers. 
(Professor  Wanklyn  at  South  Metropolitan  Gas  Co.,  Old  Kent  Road.) 


lu  1000  volumes  SH3  equals 
„  „       C03  equals  . 

„       NH3  equals 


12*1  volumes. 
15 
3-6 


Impurities  in  Condensed  but  Unwashed  Gas. 
(Lewis  T.  Wright.) 


C02 

H3S 

Grains  per 
Cubic  Foot. 

Volume 
per  Cent. 

Grains  per 
Cubic  Foot. 

Volume 
per  Cent. 

Newcastle 
Yorkshire    Silkstone 
Derbyshire         „ 
Cannels    . 

12 
12 
12  to  19 

30 

1-5 
1-5 
1-5  to  2-3 
3-7 

9 

8 
6  to  12 

3  to    6 

1-4 
1-3 

1  to  2-0 
0-5  to  1-0 

Tar  made  per  ton,  Gas  Light  and  Coke  Co.,  half-year  to  December, 
1892, 10-58  gallons. 

Average  Analysis  of  Gas  (Newcastle  Coal)  after  Condensers. 


H           ... 

Methane    .         .     . 
Carbon  Monoxide  . 
Hydrocarbons 
light 
C02  .        .        .    . 

47  per  cent. 
35         „ 

5         » 
3-5 

i-o 

1-5 

N 
H3S 
NH3     . 
Cyanogen 
CS,      .        . 
Napthalene     .     . 
( 

3'0  per  cent. 
1-7        „ 
0-7        „ 

o-i      „ 

0-03       „ 

o-oi     „ 

;Butterfield.) 

NH3  at  outlet  of  condensers,  say  300  grains  per  100  cubic  feet. 


GE. 


258  GAS  ENGINEER'S  POCKET-BOOK 


EXHAUSTERS,  ETC. 

By  exhausting  at  120°  F.,  and  passing  gas  direct  to  the  scrubbers, 
an  increase  of  from  '5  to  -75  candle  resulted  at  Croydon.  To  relieve 
the  consequent  back  pressure  in  scrubbers,  warm  water  was  tried,  but 
nearly  double  the  water  was  required  to  remove  the  ammonia  from 
the  gas. 

When  byepassing  the  condenser  the  exhauster  frequently  becomes 
choked  with  sticky  tar. 

Temperature  of  gas  at  exhauster  usually  110°  to  120°  F.  without 
fcmdensers  giving  110°  F.  at  inlet  of  condenser. 

Increase  of  pressure  raises  the  inflammability  of  gaseous  mixtures 
having  a  combustible  gas  as  one  of  their  ingredients. 

One  of  the  evils  of  over-exhausting  is  the  admission  of  furnace 
gases  with  the  coal  gas,  and  the  consequent  deterioration  of  the 
illuminating  power  of  the  latter  ;  another  is  the  increase  of  fixed 
ammonia  and  reduction  of  free  ammonia  by  the  admission  of  air  or 
furnace  gases. 

1  per  cent,  air  has  no  effect  on  illuminating  power. 

2£  per  cent,  air  lowered  17-candle  gas  to  13*45  candles  at  Ramsgate. 


„  „ 

5         „  „  „  „        10-59 

Use  Creosote  Oil  as  a  Lubricant  for  foul  gas  exhausters  (Mr.  Bacon,  of 
B.  Donkin  &  Co.).  It  is  also  said  that  castor  oil  forms  the  best 
lubricant  for  exhauster,  and  should  have  specific  gravity  '960  ;  if 
below  '955  it  is  impure.  Another  test  of  purity  consists  in  adding 
zinc  chloride,  and  then,  if  pure,  the  oil  will  turn  yellow. 

Sperm  oil  may  also  be  tested  with  zinc  chloride,  but  this,  if  pure, 
turns  milky. 

For  lubrication  of  the  working  parts  of  the  exhauster,  a  mixture  of 
pure  colza,  tar,  oil,  and  naptha  has  been  found  the  best  for  the  purpose. 

In  the  use  of  •  oil  for  lubrication  uniformity  of  distribution  is  as 
important  as  the  regularity  of  supply.  A  dry  spot  on  a  bearing  will 
at  once  cause  heating,  and,  if  allowed  to  continue,  cutting  will  be  the 
result.  No  oil  has  yet  been  made  that  can  economically  lubricate  all 
the  journals  of  a  mill.  An  oil  running  a  heavy  engine  would  not  do  to 
run  a  spindle  or  a  fast-revolving  dynamo.  The  former  runs  slowly, 
and  has  great  pressure  and  strain  on  its  journals,  and  consequently 
requires  an  oil  that  will  not  spread  too  quickly,  but  with  low  gravity 
and  high  viscosity.  The  latter  needs  a  pure  mineral  oil,  viscous  and 
quick  spreading,  to  enable  it  to  enter  into  the  closest  parts  of  the 
bearing  as  rapidly  as  the  speed  at  which  it  revolves  necessitates. 
Mineral  lubricants,  or  compounds  of  mineral  and  animal,  are  the 
safest,  and  produce  the  best  results.  Professor  Thurston  says, 
"  Rancid  oil  will  attack  and  injure  machinery.  Mineral  oil  does  not 
absorb  oxygen,  whether  alone  or  in  contact  with  cotton  waste,  and 
cannot,  therefore,  take  fire  spontaneously  ;  animal  and  vegetable  oils 
do.  Mineral  lubricating  oils  are  used  on  all  kinds  of  machinery  : 
they  are  the  safest  and  cheapest  lubricants,  and  generally  superior  to 


COMBUSTION    OP    FUELS. 


259 


animal  and  vegetable  oils  and  greases."  A  mineral  oil  flashing  below 
300°  is  unsafe.  Gumming  is  due  to  the  action  of  free  acid  upon  the 
metal  bearings  of  machinery.  J.  J.  Kedwood  remarks,  "  Mineral  oil 
has  the  least  action  on  metals,  none  on  iron  or  brass  ;  tallow  oil 
has  most  action  on  iron  ;  castor,  olive,  and  lard  oils  have  most  action 
on  brass  ;  rape  seed  has  most  action  on  copper." 

Heat  of  Combustion  of  Various  Fuels. 


Substance. 

Average  Heat  from 
1  Ib.  Fuel. 
Thermal  Units. 

Equivalent 
Evaporation  from 
and  at  212°  F. 
per  Ib.  of  Fuel, 
in  Ibs.  Water. 

Carbon  (pure)        .... 
Coal  gas    
Coal  gas,  per  cubic  foot,  at  62°  F. 
Coal,  good  average  quality    . 
Coke          
Hydrogen      ..... 

14,560 
17,800 
630 
14,700 
13,500 
62,000 

15-07 
18-43 
0-70 
15-22 
13-87 
64-20 

Peat  (dessi  cated)       .        .         .     . 
Peat,  25  per  cent,  moisture    . 
Petroleum  oils  (benzine,  etc.) 
Petroleum  crude    .... 
Petroleum  refuse,  "  astaki  "       .     . 
Straw     
Sulphur     
"Wood,  air  dried     .... 
Wood,  dessi  cated       .... 
Wood,  charcoal  dessicated     . 

10,000 
7,000 
27,500 
20,400 
20,000 
8,000 
4,000 
8,000 
11,000 
13,000 

10-35 
7-25 
28-56 
21-13 
20-70 
8-40 
4-14 
8-28 
11-39 
13-46 

Theoretically,  11  Ibs.  air  is  required  per  1  Ib.  coal  to  supply  the 
necessary  oxygen  ;  practically,  22  Ibs.  air  is  required. 
1  Ib.  coke  evaporates  about  9  Ibs.  water. 
1  Ib.    „  „  „      |th  cubic  foot  water. 

1  Ib.  coal  „  „      9  Ibs.  water. 

1  Ib.  slack  4  Ibs. 


Pounds  of  Water  Evaporated  per  Ib.  of  Fuel. 
(B.  Donkin  &  Co.) 

Breeze  or  dust  gas  coke  as  burnt  on  Perret's  grate,  5|  Ibs.  water. 
Dust  Welsh  coal  „  „  „         8J         „ 

Ordinary  Welsh  coal  on  ordinary  grate  .     9  „ 

Large  gas  coke  „  „  7£         „ 

Another  authority  gives  : — 

Lbs.  of  water  evaporated  at  212°  per  Ib.  of  fuel. 
7'4  Ibs.  per  Ib.  breeze. 
7-5  Ibs.  per  Ib.  coke. 
11-4  Ibs.  per  Ib.  Welsh  coal. 

62 


260 


GAS  ENGINEER'S  POCKET-BOOK. 


Kelative  Heating  Power  of  Fuel,     (Fritz.) 


Lbs.  of  Water  Evaporated  by 

1  Ib.  of  Fuel. 

Fuel. 

Theoretical. 

In    Steam             In  Open 
Boilers.                 Boilers. 

Anthracite 

12-46 

_ 



Coal    

11-51 

5-2    to  8 

5-2 

Charcoal. 

10-77 

6            6-75 

3-7 

Coke  

9  to  10-8 

5            8 



Brown  Coal     . 

7-7 

2-2         5-5 

1-5    to  2-3 

Peat   

5-5  to  7-4 

2-5         4-5 

1-7     „   2-3 

Wood      .... 

4-3  to  5-6 

2-5         3-75 

1-85  „   2-1 

Straw          .        .        .    . 

3-0 

1-86       1-93 

— 

Gas  reduced  to  Ibs.  coal  . 

— 

4       6 

— 

In  heating  boilers  the  average  amount  of  theoretical  heating  power 
of  fuel  that  is  utilised  is  only  47  per  cent.,  the  remainder  being  lost 
through  imperfect  combustion,  radiation,  and  other  causes. 


Evaporative  Power  of  Fuel. 
Another  set  of  tests  gave  : — 
Ib.  coke  evaporates  9    Ibs.  water    (feed  water  supplied  at  212°  F.). 


coal  „         9 

;;  slack      „     4  ;, 

,,  oak  (dry)  „         4£   „        „ 
„   pine  „         2J   „ 

An  average  of  27  coals  for  fuel  measured  about  40£  cubic  feet  per 
ton. 

Cost  of  evaporating  10  Ibs.  of  water  from  steam  boilers. 
Breeze        at    4/6  per  ton  =  Q'OSGd. 
Coke          at  12/-  per  ton  =  0'097d. 
Welsh  coal  at  20/-  per  ton  =  0-107d. 

Coke  and  coal  are  usually  considered  of  equal  calorific  value,  weight 
for  weight. 

Boiler  should  be  fed  by  small  quantities  and  often,  so  that  the 
draught  of  the  chimney  does  not  carry  away  the  fuel  improperly  com- 
bined to  form  a  permanent  invisible  gas  ;  smoke  is  only  the  re- 
condensing  of  gases  that  having  been  liberated  by  heat,  have  been 
allowed  to  cool  back  again  and  lapse  back  to  their  constituent  parts 
before  chemical  union  has  arranged  their  molecules  so  as  to  render 
them  invisible,  when  they  enter  the  atmosphere  and  become  absorbed 
in  it. 

Andrew's  patent  fuel  for  boilers  and  retort  furnaces  consists  of 
40  gallons  tar  to  1  chaldron  (21£  cwt.)  breeze,  and  sets  hard  in  a  few 
days. 


BOILER   INCRUSTATIONS.  261 


Average  Water  Consumption  in  Steam  Engines. 

Non-condensing  .        .  25    to  40  Ibs.  per  I.H.P.  per  hour. 

Condensing         .  .     .  18    „  30  „            „                 „ 

Compound       .  .         .  16     ,,  20  .,             „                  „ 

Triple  expansion  .     .  13J  „  15  „            „                „ 

Heat  feed  water  of  boilers  to  212°  F.  if  possible. 
The  usual  course  adopted  by  the  engine  and  boiler  minders  is  to 
inject  tallow  into  the  boiler  to  prevent  priming. 

To  Prevent  Boiler  Incrustations. 

Two  ounces  muriate  of  ammonia  in  boiler  twice  a  week. 

Carbonate  of  soda. 

Frequent  blowing  off. 

Any  fatty  deposit  on  the  interior  surface  of  a  boiler-plate  greatly 
hinders  the  transmission  of  heat.  (J.  Hirsh.) 

Use  caustic  soda  and  soda  ash  for  prevention  of  depositions  of 
carbonate  and  sulphate  of  lime  in  boilers.  1£  ounces  pure  caustic 
soda  per  1,000  gallons  for  each  grain  carbonate  of  lime  in  feed  water, 
and  If  ounces  carbonate  of  soda  (soda  ash)  per  1,000  per  grain. 

Remove  all  sediment  from  boiler  through  blow-off  cock  every 
twelve  hours. 

Ordinary  feed  water  may  be  said  to  contain  *05  per  cent,  solid 
matter,  or  35  grains  per  gallon  (in  a  boiler  of  100  H.P.  this  equals 
1  Ib.  solid  matter  deposited  per  hour).  By  heating  the  feed  water  a 
large  proportion  of  this  may  be  kept  out  of  the  boilers. 

Test  for  Pure  Water. 

1.  Evaporate  a  few  drops  on  a  piece  of  glass  ;  scarcely  a  trace  of 
solid  matter  should  remain. 

2.  Add  nitrate  of  silver  ;   no   turbidity  (indicating   chlorides   or 
hydrochloric  acid)  should  be  produced. 

3.  Add  chloride  of  barium  ;  there  should  be  no  turbidity  (indi- 
cating sulphates). 

4.  Add  oxalate  of  ammonia  ;  there  should  be  no  turbidity  (indicat- 
ing lime). 

5.  Add  hydrosulphuric  acid;    there    should    be    no    dark  tinge 
(indicating  lead  or  copper). 

Carbonates  of  lime  and  magnesia  are  deposited  slowly  at  150°  F., 
but  at  from  280°  to  300°  the  deposition  is  rapid  (except  2  or  3  grains 
per  gallons,  which  remains  dissolved). 

Sulphate  of  lime  is  deposited  at  307°. 

11  Ibs.  air  required  theoretically  for  1  Ib.  coal  burnt,  but  double 
this  necessary  with  natural  draught  in  boilers. 

The  proportion  of  carbonic  acid  gas  in  the  boiler  flue  should  lie 
between  11  per  cent,  with  bituminous  and  15  per  cent,  with  anthracite 
coals,  with  a  small  percentage  of  oxygen  and  no  carbonic  oxide. 

Heat  at  outlet  of  chimney  may  be  reduced  to  300°  C.  without 
injury  to  draught. 

When  a  jet  photometer  is  fixed  in  the  exhauster  house,  the  gas 
should  be  purified  by  means  of  small  lime  and  oxide  purifiers  before 
admission  to  the  photometer. 


262  GAS  ENGINEER'S  POCKET-BOOK. 


WASHING  AND  SCRUBBING. 

Gas  should  be  free  from  tar  before  it  enters  the  washers  and 
scrubbers,  or  the  efficient  working  of  the  latter  will  be  impaired. 

Clean  water  scrubbers  require  from  2  to  3  gallons  water  per 
1 .000  cubic  feet  of  gas  passed  through  them. 

Quantity  of  water  required  in  standard  washer  scrubber  10  gallons 
per  ton.  This  removed  241  grains  NH3  and  reduced  the  C00  and 
1I2S  some  30  per  cent. ;  50  square  feet  of  wetted  surface  is  exposed 
to  the  gas  per  cubic  foot  of  machine. 

13'7  gallons  of  water  used  in  Kirkham  Hulett  and  Chandler's 
washers  per  ton  of  coal  carbonized  and  liquor  produced  was  of 
15  ounces  strength.  (King's  Cross  Works,  1881.) 

Water  at  ordinary  temperature  absorbs  700  times  its  volume  of 
ammonia  gas. 

Cold  water  will  absorb  about  1,000  times  its  bulk  of  ammonia  gas. 

Water  in  scrubbers  should  not  be  lower  than  50°  or  hydrocarbons 
will  be  deposited. 

At  a  temperature  of  60°  F.  liquor  of  14  ounces  strengtli  cannot 
reduce  the  ammonia  in  the  gas  it  is  in  contact  with  to  a  lower  degree 
than  54  grains  per  100  cubic  feet.  (L.  T.  Wright.) 

At  a  temperature  of  183°  F.  water  will  not  absorb  ammonia. 

Where  there  is  plenty  of  washing  and  scrubbing  room,  water  at 
70°  F.  lias  been  used  and  good  results  obtained. 

If  the  water  used  to  abstract  ammonia  is  warm  it  wWl  afterwards 
freely  give  off  ammonia  into  the  air. 

The  water  used  in  scrubbing  has  a  distinctly  deteriorative  action 
on  the  illuminating  power  of  the  gas. 

If  gas  be  lowered  in  temperature  below  40°  F.  it  has  to  be  raised 
in  scrubbers,  and  napthalene  will  be  deposited  in  them. 

Average  yield  of  ammonia  per  ton  equals  6-8  Ibs..  or  1-5  per  cent,  by 
volume,  or  467  grains  per  100  cubic  feet  at  outlet  from  retorts. 

About  one-half  of  the  total  ammonia  in  the  gas  is  removed  by  the 
scrubbers. 

NH3  removed  by  condensation      .         .         .    42-7  per  cent. 
NH8          „  first  scrubber          .        .     .     43-3         „ 

NH3          „  second    „  .        .        .14-0        „ 

(C.  Hunt.) 

Ammonia  is  produced  in  a  greater  amount  during  the  earlier  period 
of  the  charge,  and  cyanogen  during  the  latter  hours. 

Lancashire  and  Yorkshire  coal  generally  contains  a  larger  propor- 
tion of  ammonia  than  Durham  coal. 

The  ammonia  in  Midland  Counties  coal  varies  from  G2-7  to 
14T2  ounces  per  ton. 

Equal  and  thorough  wetting  of  the  material  in  the  scrubber  is 
necessary  to  ensure  good  working. 

With  tower  scrubbers  extreme  cold  may  have  a  detrimental  effect 
on  the  illuminating  power. 


SCRUBBING,  263 

About  26  to  36  gallons  of  10  ounce  liquor  are  produced  per  ton  of  coal 

If  gas  be  passed  through  a  coke  or  clinker-filled  scrubber,  saturated 
with  tar.  it  will  injure  the  gas  by  as  much  as  2  candles. 

A  lead-lined  scrubber  containing  weak  acid  might  be  used  for  the 
elimination  of  the  last  few  grains  of  ammonia,  and  thus  water  be  saved. 

If  liquor  which  has  once  passed  through  a  scrubber  be  purified 
partly  from  H2S  and  C02,  it  can  be  made  to  remove  nearly  all  the 
H2S  and  much"of  the  C02"  when  used  again  in  the  scrubber. 

In  ammoniacal  liquor,  |ths  of  the  ammonia  is  combined  with  C0a 
and  H2S  and  can  be  freed  by  boiling,  the  remaining  ith  is  combined 
with  hydrochloric,  sulphuric,  and  other  acids  which  cannot  be  freed 
by  boiling. 

"lOOO  cubic  feet  crude  Newcastle  coal  gas  contains  about  8  cubic 
feet  H2S,  25  cubic  feet  C0a. 

About  eight  times  the  ammonia  present  in  the  crude  gas  would  be 
required  to  eliminate  all  the  C02  and  H2S  in  the  gas. 

A  strong  solution  of  ammoniacal  liquor  is  required  to  effectually 
remove  as  large  a  proportion  as  possible  of  the  H2S  and  C02  from  the 
gas  in  the  washers. 

Of  the  total  volume  of  ammonia  in  the  gas  there  will  be  1-2  per 
cent,  available  for  combining  with  the  C02  and  the  hydro-sulphuric 
acids  which  will  be  able  to  remove  0'6  per  cent,  of  C00  and  0*18  per 
cent.  H2S. 

One  combining  equivalent  NH3  will  absorb  C02  or  H2S  to  the 
extent  of  H  to  1^  combining  equivalent  of  one  or  both  of  these  acid 
bodies.  (Butterfield.) 

100  volumes  NH3  combine  with  about  12J  volumes  H2S. 

100  volumes  NH3  combine  with  about  50  volumes  C02. 

In  a  washer  using  7  ounce  liquor  which  thus  became  one  of  14 
ounce  strength,  the  latter  was  found  to  contain  5,000  cubic  inches  of 
C02and  H2S  equal  to  357  cubic  inches  per  ounce  of  strength,  and  the 
cost  of  dry  purification  by  the  dry  process  was  reduced  by  20  per  cent. 

Maximum  tension  of  ammonia  gas  in  coal  gas  is  about  0'45  inches 
mercury. 

When  the  quantity  of  water  is  reduced  owing  to  smaller  makes, 
the  impurities  in  the  gas  travel  further  forward  in  the  apparatus 
before  being  removed  from  the  gas. 

Scrubbers  remove  about  2  grains  CS2  per  100  cubic  feet. 

Ammoniacal  liquor  will  remove  ammonia  from  the  gas  in  propor- 
tion to  its  own  strength  of  ammonia  only,  therefore  too  strong 
ammonia  used  over  the  first  scrubber  may  have  the  effect  of  increas- 
ing the  quantity  of  the  ammonia  in  the  gas  if  the  amount  present 
before  the  gas  enters  the  scrubber  is  less  than  the  equivalent  quantity 
in  the  liquor  being  used  for  washing  purposes. 

In  gas  liquor  of  average  strength  there  is  generally  from  60  to  70 
per  cent,  by  volume  of  carbonic  and  hydro -sulphuric  acid  in  pro- 
portion to  the  volume  of  ammonia. 

1  gallon  10  ounce  liquor  contains  4,704  cubic  inches  C02  and 
1,362  cubic  inches  H2S,  with  6,066  cubic  inches  other  foul  gases  or 
equal  to  57  cubic  feet  C02,  16  cubic  feet  HaS.  (G.  Livesey.) 

1  cubic  foot  NHS=  316-77  grs. 


264 


GAS  ENGINEER'S  POCKET-BOOK. 


The  roost  probable  proportion  of  ammonia  to  C02  in  gas  liquor 
would  be  2  volumes  NH3  to  1  volume  C0a,  but  with  NH,  and 
H2S,  1  of  NH3  to  1  of  H0S  is  more  likely. 

Ammonia  combines  with  CO2  to  form  ammonium  bicarbonate 
(NH4HC03). 

Ammonia  combines  with  ELS  to  form  ammonium  sulphohydrate 
(NH4HS)  ;  or, 

Ammonia  combines  with  C02  to  form  ammonium  monocarbonate 
(NH4)2C03. 

Ammonia  combines  with  H2S  to  form  ammonium  sulphide. 

Ammoniacal  liquor  is  a  weak  solution  of  ammonium  bicarbonate 
(NH4HC03),  ammonium  sulpho-hydrate  (NH4HS),  together  with 
appreciable  quantities  of  sulpho-cyanide  (NELCNS)  and  thio-sulphate 
(NH,)2S203.  (Lancet.} 

Analysis  of  Ammoniacal  Liquor.     (Professor  Lewes.) 


Ammonia  sulphide 
„        carbonate 
„         chloride 
„        thio-cyanate 
„        sulphate 
„        thio-sulphate 
„        ferro-cyanide; 

JFree 
•  Fixed 

Grammes  per  Litre. 
3-08 
39-lfi 
14-28 
1-80 
0-19 
2-80 
0-41 

Water  will  dissolve  at  60°  F.  and  30  inches  barometer,  an  equal 
volume  of  C02. 

Water  will  dissolve  at  32°  F.  If  volume  of  C02. 

Water  will  dissolve  at  23°  F.  4-37  volumes  of  HaS,  and  -001  volume 
of  CS2. 

Water  will  dissolve  at  60°  F.  and  30  inches  barometer  783  volumes 
of  NH3. 

Water  will  dissolve  at  183°  F.  no  NH8. 

1°  Twaddel  equals  about  two  ounces  strength  by  distillation. 


Factor  for  Rendering  Degrees  Twaddel  into  Ounces  Strength. 
(Lewis  T.  Wright.) 


Description  of  Liquor. 

Saturation. 

Distillation. 

Natural      

2-18 

2-54 

1-80 

2-43 

„        caimel  coal  . 

1-68 

2-22 

Final  product        .        t         .     . 

1-62 

2-00 

M                    J»                     •                f                •                » 

1-68 

2-04 

J»                    ))            •                *                i                •         • 

1-59 

1-92 

From  clean  water  scrubbers 

— 

1-64  to  1-83 

CYANOGEff.  265 

Caking  coals  contain  from  1-56  to  1-9  per  cent.  N,  but  of  this  amount 
only  11-59  to  15*72  per  cent,  comes  off  as>NH3  during  distillation. 

Yield  of  ammonia  greatest  at  medium  heats.     (L.  T.  Wright.) 
.  Of  the  total  N  in  the  coal,  14-5  per  cent,  passes  off  as  ammonia, 
1-56  per  cent,  as  cyanogen,  48 '68  per  cent,  in  coke,  35-26  per  cent,  in 
the  gas.     (Professor  W.  Foster.) 

The  greater  the  proportion  of  fixed  ammonia  the  less  the  purifying 
power  of  the  liquor  for  the  elimination  of  H2S  or  CO,. 

The  liquor  from  the  scrubbers  contains  carbonate  and  sulphide  of 
ammonium,  some  free  alkali  and  sulphocyanide,  hyposulphite  and 
sulphate. 

If  sufficient  ammonia  be  presented  to  the  crude  gas  all  the 
H2S,  C02,  and  C2S  will  be  removed. 

if  liquor  could  be  made  to  give  off  the  H2S  and  C02  which  it  has 
taken  up  in  the  scrubbers  and  could  be  used  over  again  these 
impurities  might  be  removed  almost  entirely  by  the  ammonia. 

Hill's  Process  of  "  ammonia  purification  "  consists  of  bringing  the 
liquor,  after  use  in  the  scrubbers,  to  nearly  boiling  point,  when  the 
CO2  and  H2S  are  driven  off  and  the  ammonia  can  then  be  used  again 
in  the  scrubbers  for  the  further  elimination  of  C02  and  H2S. 

By  Hill's  process  the  liquor  was  heated  to  180°  F..  when  the 
C02  and  H2S  were  driven  off  as  follows  :— NH4HC03  =  NH3  +  H2O  + 
C02,  and  NH4HS  =  NH3  +  H2S. 

To  prevent  the  loss  of  ammonia  the  gases  were  passed  through  a 
scrubber  supplied  with  liquor  at  160°  F.  which  it  was  supposed  would 
arrest  any  ammonia  gases.  To  obtain  sufficient  ammonia  to  remove 
all  the  C02  from  the  crude  gas,  the  liquor  has  to  be  treated  twice  for 
the  removal  of  the  CO^  previously  taken  up. 

Cyanogen. — The  quantity  of  cyanogen  recoverable  from  coal  gas 
varies  with  the  temperature  of  carbonization,  from  5,000  grains  with 
low  heats  to  10,000  grains  with  high  heats  per  ton  of  coal. 

The  most  favourable  temperature  in  the  retorts  for  the  formation 
of  cyanides  equals  2,200°  F. 

Cyanogen  is  the  gaseous  compound  of  carbon  and  nitrogen. 


To  Recover  the  Cyanogen. 

First  remove  all  the  NH3  and  then  pass  the  gas  through  soda  or 
potash  in  solution  in  presence  of  an  iron  salt,  when  from  4  to  4£  Ibs. 
of  crystallized  ferrocyanide  of  soda  or  potash  is  recoverable  per 
ton  of  coal. 

Spent  products  in  gas  works  rarely  contain  more  than  15  per  cent, 
of  ferrocyanide  of  potassium.  (M.  Perthuis.) 

Ammoniacal  liquor  made  per  ton,  Gas  Light  and  Coke  Co.  half 
year  to  December,  1892  : — -279  butts  per  ton  of  10  ounce  strength 
by  distillation, 


266  GAS  ENGINEER'S  POCKET-BOOK. 

Impurities  in  Coal  Gas  after  passing  Scrubbers. 
(Butterfield.) 

H2S         500  to     800  grains  x 

CO2         700  to  1,100     „      L  per  100  cubic  feet. 

CS2  30  to      45      .,      J 

Average  Composition  of  Gas  after  leaving  Scrubbers. 
(Professor  V.  B.  Lewes.) 

H  48-55  per  cent,  by  volume. 

Methane 39' 70 

Illuminants 3-30 

C02 2-50 

CO 2-00 

O 0-45 

N 3-50        1^ 

If  the  scrubbing  is  properly  done,  the  gas  should  not  contain  more 
than  1-4  per  cent.  C02, 0*3  per  cent.  H2S,  and  from  38  to  42  grains  CS2 
per  100  cubic  feet  with  no  ammonia. 

Gas  after  leaving  scrubbers  contains  about  400  grains  H2S  and  35 
to  40  grains  OS,  and  other  sulphur  compounds. 

There  is  generally  some  ammonia  (say  50  grains  per  100  cubic  feet) 
at  outlet  of  tower  scrubbers,  but  if  a  washer-scrubber  be  in  use  the 
quantity  will  be  reduced  to  2  grains  per  100  cubic  feet. 

When  water  contains  even  traces  of  ammonia  it  will  not  take  up 
the  last  grains  of  ammonia  from  the  gas. 

The  formation  of  cyanogen  compounds  is  due  to  a  secondary 
reaction  between  the  ammonia  primarily  formed  and  the  glowing 
carbon  :  C2  +  4NH3  =  2NFf4CN  +  2H3  ;  this  requires  a  high 
temperature. 


PURIFICATION.  267 


PUF.IFYING. 

Gas  loses  about  3  per  cent,  by  volume  in  passing  through  the 
purifiers,  due  to  the  elimination  of  the  C00  (2'25  per  cent.)  and  H2S 
(0-75  per  cent). 

25  cubic  feet  of  C02  per  1,000  cubic  feet  gas  reduces  illuminating 
power  about  two  candles,  or,  in  other  words,  1  per  cent.  C02 
diminishes  illuminating  power  5  per  cent.,  if  gas  is  of  16  c.  p. 

CO  is  present  in  coal  gas  to  the  extent  of  from  3  to  8  per  cent. 

I'l  per  cent.  S  in  coal  equals  1*2  per  cent,  of  H0S  in  the  gas. 

(Butterfield.) 

Crude  gas  contains  about  8  feet  of  sulphuretted  hydrogen  per 
1.000  feet  of  gas  from  Newcastle  coal. 

Sulphuretted  hydrogen  is  1  part  H,  16  parts  S ;  specific  gravity 
is  T178  ;  100  cubic  inches  weigh  36*51  grains. 

In  ordinary  use  a  purifier  is  turned  off  before  it  has  ceased  to 
remove  H2S,  the  usual  test  being  that  the  next  box  shows  a  foul  test. 

Oxide  of  iron  will  at  times  absorb  CS2.  but  will  again  give  this  off 
quite  suddenly,  possibly  owing  to  the  affinity  of  S  for  CS2,  which  can 
be  disturbed  by  a  slight  increase  in  temperature. 

If  gas  containing  CS2  is  passed  through  a  mixture  of  sawdust  and 
sulphur  the  quantity  of  CS2  will  be  reduced  50  per  cent. 

Oxide  of  iron,  after  fouling,  contains  some  free  sulphur  and  iron 
sulphide  ;  and  revivification  converts  this  into  sulphur  and  hydrated 
iron  oxide  by  the  action  of  moisture  and  air. 

Analysis  of  Bog  Ore  (Dry  basis). 

Ferric  oxide 60  to  70  per  cent. 

Organic  matter 15  to  25        „ 

Silica 4  to    6       „ 

Alumina        ......  1                 „ 

When  in  use  the  material  would  contain  about  30  to  40  per  cent, 
water. 

Bog  ore  is  a  hydrated  sesquioxide  of  iron  (Fe0,  O3,  3  H00). 

Composition  of  Bog  Ore  : — 

H20 50  per  cent. 

Hydrated  oxide  of  iron,      active          .  20)  q9 

„  „      inactive       .      12}  * 

Vegetable  matter 18      ,, 

Bog  ore  when  ready  to  place  in  purifier  should  only  contain 
25  per  cent,  moisture. 

Westbury  Natural  Oxide  contains  about — 

66  per  cent,  hydrated  peroxide  of  iron, 
28         „        earthy  matter, 
6         „        uncombined  water. 

(N.  H.  Humphreys.) 

Bog  ore  contains  30  per  cent.  Fe2,  O3,  and  55  per  cent,  moisture. 


268  GAS  ENGINEER'S  POCKET-BOOK. 


Analysis  of  O'Neill's  Oxide.     (June,  1875.) 

Water  per  cent 22-30 

Fibre        .........  11-60 

Peroxide  of  iron 65-42 

Silica -57 

Loss                                                                        .  -11 


100-00 

One  cubic  foot  of  oxide  weighs  56  Ibs. 

"One  ton  of  oxide  should  eliminate  the  H3S  from  3,000,000  cubic 
feet  of  Newcastle  coal  gas,  which  contains  about  8  cubic  feet  of  H2^ 
per  1,000." 

"  An  average  quantity  of  oxide  for  2,000,000  cubic  feet  of  gas  is  ono 
ton  when  oxide  only  is  used." 

"  One  ton  bog  ore  should  purify  from  1,250.000  to  1,500,000  cubic 
feet  of  gas  from  H2S  before  becoming  spent." 

It  ia  better  when  using  new  oxide  for  the  first  time  to  mix  a  little 
old  with  it,  to  reduce  the  percentage  of  moisture. 

A  little  old  oxide  mixed  with  new  assists  its  action  at  first,  as  will 
also  the  presence  of  a  slight  quantity  of  ammonia  in  the  gas. 

One  equivalent  of  hydrated  peroxide  combines  with  about  three 
equivalents  of  H2S. 

36  parts  of  hydrated  peroxide  of  iron  will  combine  with  17  parts  of 
H2S. 

Room  must  be  allowed  for  expansion  of  material  upwards  when 
revivified  in  situ. 

Oxide  should  be  laid  in  layers  of  from  12  to  18  inches  thick. 

Best  method  of  using  oxide  is  2  layers  of  18  inches  thick. 

(Hawkins.) 

Oxide  of  iron  is  laid  as  thick  as  2  feet  6  inches  in  some  purifiers. 

A  thick  layer  of  oxide,  say  3  feet  thick,  will  often  have  to  be  turned 
off,  on  account  of  back  pressure,  when  only  just  put  to  work,  but,  as  a 
rule,  with  thick  layers  of  oxide  no  great  increase  of  pressure  need  be 
feared  if  there  be  good  scrubbing  and  washing  beforehand. 

Oxide  usually  laid  about  10  inches  to  12  inches  thick  on  the  grids. 

Oxide  should  be  laid  about  10  inches  thick  to  revivify. 

Gas  should  not  be  allowed  to  enter  a  purifier  much  above  the 
temperature  of  the  oxide  therein^ 

The  avoidance  by  every  possible  means  of  high  temperatures  in  the 
purifiers,  or  during  the  revivification,  of  the  spent  material  is  advis- 
able. (M.  Godinet.) 

Gas  purified  by  oxide  of  iron  is  said  to  have  a  yellow  tinge,  while 
that  purified  by  lime  is  whiter,  the  colour  of  the  former  being  due 
probably  to  the  presence  of  CO2. 


Reaction  in  Oxide  Purifiers. 

Fe203H20  +  3  H2S  =  Fe2S3  +  4  H20 ;  or 
Fe208H8O  +  3  H2S  ==  2  Fe  S  +  S  +  4  H2O. 


OXIDW   PURIFICATION.  269 

Action  of  air  when  revivifying  upon  Fe2S3  +  4  H20. 
2  Fe2S3  +  3  02  =  2  Fe2  03  +  3  Sa. 
12  Fe  S  +  9  02  =  6  Fe3  03  +  6  S2. 

Oxide  (bog  ore)  should  remove  1st  time  16  per  cent.,  2nd  6  per  cent., 
3rd  5  per  cent,  sulphur. 

Another  authority  gives^- 

Reaction  of  Oxide  of  Iron, 

(70  o/0  to  83  °/o)  Fe203H20  +  3  HaS  =  Fe2S3  +  4  H20. 
(17  %  to  30  o/o)  „  '    =  2  FeS  +  S  +  4  H20. 

When  revivifying — 

Fe2S3  +  3  0  +  HO  =  Fe203H20  +  3  S. 

Also  hydrated  oxide  of  iron  removes  H2S  as  per  equation  : — 

Fe2033  H20  +  3  H2S  =  2  Fe  S  +  6  H20  +  S,  and  is  revivified  in 
the  air  as  follows  :— 2  FeS  +  3  H20  +  20=30  +  Fe202H2O  +  2  S. 

H2S  unites  with  the  iron  and  forms  sulphide  of  iron,  the  H,  com- 
bining with  0  in  the  oxide  forming  water.  After  use  in  purifier  the 
oxide  is  in  the  form  of  sulphide  of  iron,  the  iron  absorbs  0  and  leaves 
the  sulphur  in  a  free  state. 

It  is  not  advisable  to  use  oxide  containing  more  than  55  per  cent, 
to  60  per  cent,  free  sulphur,  as  its  utility  is  impaired,  but  when 
revivified  in  situ  it  can  be  made  to  take  up  75  per  cent. 

Artificial  oxides  work  best  with  from  20  to  30  per  cent,  moisture 
bog  ores  with  10  to  20  per  cent. 

Oxide  can  be  used  until  it  has  taken  up  60  per  cent,  by  weight  of 
sulphur,  but  has  no  action  upon  C02. 

New  oxide,  when  revivifying,  combines  very  rapidly  with  the  0  in 
the  air,  causing  rapid  evolution  of  heat. 

Value  of  spent  oxide  should  be  sufficient  to  purchase  all  purifying 
material  necessary  for  purification  of  gas  from  H2S. 

It  has  been  found  that  by  treating  spent  oxide  with  caustic,  lime, 
and  soda  sulphate  at  a  certain  temperature,  an  increased  yield  of 
sulphocyanates  and  f  errocyanides  are  obtained  equal  to  about  40  per 
cent,  above  that  obtainable  by  treatment  with  water. 

Analysis  of  Spent  Oxide,    (J.  Hepworth.) 

Per  Cent. 

H20 14-0 

S 60-0 

Organic  substances  insoluble  iii  alcohol        .        .         .  3'0 
Organic  substances  soluble  in  alcohol  consisting  of 
calcium  ferrocyanide  and  sulphaequinde,  ammonium 

cyanidequinde,  sal-ammoniac  hydrocarbon  .         .     .  1'5 

Clay  and  sand 8'0 

Calcium  carbonate,  ferric  oxide,  &c 13-5 

ioo-o 

About  one-half  the  total  sulphur  present  in  coal  passes  forward  to 
the  purifiers. 

The  quantity  of  H2S  requiring  to  be  removed  by  the  purifier  may 
range  from  200  to  2,000  grains  per  100  cubic  feet 


270  GAS  ENGINEER'S  POCKET-BOOK. 

Order  of  Value  for  Purifying  Coal  Gas  of  the  Principal  Limestones  of 
this  Country,     (Hughes.) 

1.  The  white  chalk  limestone  of  Merstham,    Dorking,  Chaiiton, 
Erith,  and  other  parts  of  the  chalk  range  surrounding  the  metropolis. 

2.  The  grey  chalk  limestone,  from  the  lower  beds  of  chalk. 

3.  The  blue  beds  of  the  upper  and  middle  Oolites. 

4.  The  lower  white  and  grey  limestones  of  the  Oolites. 

5.  The  most  calcareous  and  crystalline  beds  of  the  carboniferous  or 
mountain  limestone,  colours  grey  and  bluish. 

6.  The  magnesian  limestone  of  Yorkshire  and  Derbyshire. 

7.  The  white  lias  limestone. 

8.  The  blue  lias  limestone. 

9.  The  Silurian  limestone  of  Wenlock,  Dudley,  &c.,  and  the  coraline 
limestones  of  Plymouth  and  the  neighbourhood. 

Theoretical  value  of  chalk  when  made  into  lime  is  100  Ibs.  chalk 
equals  56  Ibs.  CaO  as  per  equation  : — 

CaCO3=Co2  +  CaO. 
100  =  44  +  56 

In  practice  1  ton  chalk  makes  on  an  average  1  yard  lime ;  (13,596 
tons  chalk  made  13,300  yards  lime).  (Actual  experiment,  17th  May, 
1893.) 


Lime. 

25  striked  bushels  or  100  pecks  equals  1  hundred  of  lime. 
46.656  cubic  inches,  1  cubic  yard,  or  27  cubic  feet  containing  21§ 
bushels,  equal  100  lime. 

]  bushel  of  quick  lime  weighs  about  70  Ibs. 
]  cubic  foot  stone  „         „        „          54  „ 
1  cubic  yard  quick  „         „         „      1,460  „ 
1  ton  „  equals  32  bushels. 

About  40  Ibs.  of  lime  are  required  to  purify  a  ton  of  coals  in  large 
works. 

Lime  used  in  large  and  medium  sized  works  in  purification  with 
oxide  or  other  supplemental  method  ranges  from  3'3  to  5'5  cubic 
yards  per  million  cubic  feet  of  gas. 

By  the  rotation  method  of  purifying,  1  yard  unslaked  lime  is 
required  per  35  tons  of  coal  used. 

165  Ibs.  Irish  unslaked  lime  will  clean  about  35,000  cubic  feet  of 
gas. 

Quantity  of  lime  required  to  extract  C02,  about  3'3  yards  per 
million  cubic  feet. 

Chalk  lime  is  best  for  purification  of  gas  from  C02. 

Lime  often  contains  5  to  20  per  cent,  of  earthy  matters  which  may 
cause  it  to  become  caked  in  the  purifiers. 


LIME   PURIFICATION.  271 

Lime  ready  for  the  purifiers  generally  contains  30  to  10  per  cent,  of 
water  above  that  required  for  the  making  of  hydrate  of  lime. 

1  bushel  quick  lime  increases  to  2^  when  slaked,  and  this  should 
purify  10,000  cubic  feet  of  gas.  (Richards.) 

Caustic  lime  when  slaked  about  doubles  in  bulk  as  CaO  +  HaO 
equals  CaH202. 

28  parts  of  lime  combine  with  9  parts  of  water  to  form  hydrate  of 
lime  or  slaked  lime. 

28  parts  of  pure  lime  will  combine  with  22  parts  of  C02. 

28  parts  of  pure  lime  will  combine  with  17  parts  of  H21S. 

74  parts  by  weight  of  pure  hydrated  lime  should  combine  with 
44  parts  of  C02  or  with  34  parts  of  HaS. 

Sometimes  when  lime  is  used  to  remove  C02,  H2S  and  C82  an 
oxide  vessel  is  used  last,  to  act  as  a  catch  purifier  to  take  up  any  H2S 
that  may  be  driven  off  from  the  sulphide  vessel. 

When  lime  only  is  used  for  purification  the  sulphur  is  wasted. 

Wet  lime  will  purify  double  or  treble  the  gas  dry  lime  will. 

(S.  Anderson.) 

Dry  CO  when  present  in  a  purifier  containing  dry  hydrate  of  lime 
will  not  combine  with  it,  but  the  addition  of  moisture  causes  the 
CaOH20  +  C02  to  become  CaOC02  +  H20. 

When  water  is  added  to  lime"  calcic  hydrate  is  formed  as  per 
equation  : — 

CaO  +  H30  =  CaOH20. 

Excessive  water  in  the  lime  will  cause  the  latter  to  cake  and  then 
impede  the  passage  of  the  gas. 

Lime  usually  laid  about  4  inches  thick  on  the  grids. 

1.650  Ibs.  of  lime  will  take  up  about  425  gallons  of  water  when 
being  mixed  up  for  the  purifier,  or  about  1  gallon  of  water  to  4  Ibs.  of 
lime. 

Lime  should  be  slaked  two  or  three  days  prior  to  use  in  purifiers  or 
it  may  cake  ;  slaking  increases  the  bulk  about  2^  times  ;  it  should  be 
as  pasty  as  possible,  and  take  the  form  of  nodules  about  f  inch  to  1 
inch  in  diameter.  Dry  lime  is  not  so  porous  or  so  efficacious  as  a 
purifying  material. 

Mr.  P.  Egner  (U.S.A.)  proposes  to  prepare  lime  for  purifying  as 
follows  : — a  thin  layer,  4  or  5  inches  deep,  of  unslaked  lime  should  be 
laid  out,  and  nearly  the  whole  quantity  of  water  poured  over  the 
lime.  As  the  lime  slakes  it  is  turned  over  with  long  pronged  rakes, 
then  one-tenth  of  its  bulk  of  screened  coke  breeze  added  and  thoroughly 
mixed  and  moistened  until  a  handful  will  stick  together  when  tightly 
squeezed 

Removal  of  Carbonic  Acid. 

Here  lime  purification  should  be  adopted ;  the  material  to  be  hot 
and  divided  in  several  layers.  No  special  system  of  revivification 
need  be  followed. 

1    Pressure  thrown  by  a  lime  purifier  with  sieves  covered  with  from 
12  to  15  inches  of  lime  should  never  exceed  1  inch  during  its  working. 


272  GAS  ENGINEER'S  POCKET-BOOK. 

Pressure  thrown  by  8  layers  of  lime  10  inches  thick  has  been  as  low- 
as  1J  inch  for  a  considerable  period. 

Lime  is  usually  placed  in  layers  of  4  to  6  inches  thick. 
Approximate   action   of  lime  on  H2S  in  purification  is  expressed 
probably  by  the  following  equation  : — 

CaOH20  +  H2S  =  CaS  +  2  H20 

Lime  meeting  C02  in  gas  without  H2S  forms  calcium  carbonate 
CaO  +  C0a  =  CaC03 

Lime  first  attacks  both  the  C03  and  H2S,  forming  carbonate  and 
sulphide  of  calcium,  but  later  the"C02,  having  a  greater  affinity  for 
the  lime,  drives  off  the  H2S  and  forms  carbonate  of  calcium  only. 

When  gas  containing  C02  and  H2S  meets  lime  : — 

CaHsOf+  2  H2S  =  CaS,  H2S  +  2  H20  ^ 

"  or 
CaH2Oa  +  H2S    =  CaS  +  2  H20  f  formed  simultaneously, 

and 
CaO  +  C0a         =  CaC03 

afterwards  the 
CaS  +  C02  +  H20  =  CaC03  +  H2S 

the  HaS  being  driven  forward  owing  to  the  greater  affinity  of  the 
C0a  decomposing  the  CaS  ;  but  if  air  is  admitted  a  certain  portion  of 
the  H2S  is  converted  into  free  sulphur  and  it  cannot  then  be  sent 
forward. 

About    70  Ibs  quicklime  is  required  per  ton  of  coal  in  small  works. 
„      130      ,,  „  „  „       „       .,     cannel. 

1  bushel  quicklime  weighs  about  70  Ibs.  =  1'3  cubic  feet. 
1  cubic  foot  chalk  lime  ,,  „  45  „  =  0€771  bushels. 
1  cubic  yard  ,,  „  ,,  1,460  „  =  20.9  „ 

1  ton  ,,  measures   ,,        32  bushels. 

Lime  ready  slaked  for  the  purifiers  should  weigh  about  90  Ibs.  per 
bushel. 

Mr.  Forstall  has  suggested  passing  the  slaked  lime  through  sieve 
with  1  inch  square  mesh  set  at  an  angle  of  70°  with  the  floor,  and  the 
lime  should  not  be  wet  enough  to  cling  to  the  sieve. 

If  lime  be  allowed  to  become  too  dry  and  powdery  C02  will  speedily 
slip,  and  if  too  wet  the  result  is  not  satisfactory ;  both  extremes 
should  be  avoided.  If  cold  gas  be  introduced  into  a  hot  material  the 
latter  is  rendered  powdery,  and  if  hot  gas  is  introduced  into  a  cold 
material  it  is  made  too  wet. 

Removal  of  the  Sulphur  Compounds. 

The  cost  of  removing  the  sulphur  compounds  may  be  taken  aa  over 
Id.  per  thousand  cubic  feet. 

Where  oxide  of  iron  is  used  there  should  be  a  large  purifying 
surface  and  prolonged  contact  with  the  purifying  material,  which 
should  be  in  one  or  several  layers  according  to  the  use  or  non-use  of 


SULPHUR  COMPOUNDS.  273 

inert  materials.  Where  revivification  is  effected  in  the  open  air,  the 
material  should  be  heaped  up  on  its  removal  from  the  purifiers,  and, 
as  soon  as  it  becomes  heated,  spread  in  layers  from  8  to  12  inches 
thick.  Where  continuous  revivification  is  employed  the  volume  of 
air  or  oxygen  should  be  injected  without  interruption  and  in  exact 
proportion  to  the  make  of  gas,  the  material  to  be  kept  warm  and 
moist.  In  the  case  of  purification  by  lime  the  material  should  be 
divided  into  several  layers  and  used  cold  if  it  is  desired  to  retain  more 
of  the  sulphide  of  carbon,  otherwise  hot.  Oxygen  should  be  employed 
for  revivification. 

Quantity  of  Sulphur  Compounds  from  Same  Coal. 

Yield  of  Gas  Sulphur  per  100  Cubic  Feet 

per  Ton.  other  than  H2S. 

grains. 
6,893        ......         13-9 

8,370  ......         19-1 

9,431        ......         26-7 

10,772  ......        36-9 

11,620        .        .        .         .         .         .         44-1 

If  C02  be  allowed  to  pass  into  a  sulphided  lime  purifier  it  will 
liberate  some  of  the  HaS  and  CS2  already  taken  up  and  form  car- 
bonate of  calcium  in  its  "place. 

If  H2S  be  allowed  to  pass  into  a  properly  sulphided  lime  purifier  it 
changes  the  monosulphide  to  a  polysulphide,  which  has  no  effect  upon 
the  CS2. 

Of  the  45  grains  S.  other  than  H2S  in  coal  gas  per  100  cubic  feet, 
the  C02  purifiers  remove  10  grains,  the  sulphided  purifiers  remove 
25  grains. 

Carbon  bisulphide  (CS2)  is  usually  removed  by  a  lime  purifier, 
through  which  a  quantity  of  gas  free  from  C02  but  containing  H2S 
has  been  passed,  the  H2S  combining  with  the  lime  to  form  sulphide 
of  lime,  which  latter  will  remove  practically  all  the  CS3. 

The  removal  of  the  sulphur  compounds  is  not  rendered  more  certain 
by  the  admission  of  1  to  2  per  cent,  of  air  at  Nos.  3  or  4  purifiers  at 
Kotherhithe.  (A.  F.  Browne.) 

Probable  action  in  sulphided  lime  purifiers. 

CaS  +  CSa=CaCS8 
or, 

CaSH20  +  CS2  ==  CaCS3+H2O 
or, 

CaS5  +  CS2  =  CaS2CS2  +  S3 

The  calcium  pentasulphide  may  also  combine  with  the  0  admitted 
in  the  air  thus  :  — 


or  with  C02  thus  :—  . 


G.E. 


C02 


274  GAS  ENGINEER'S  POCKET-BOOK. 

Laming  material  consists  of  sulphate  of  iron,  250  kilogrammes ; 
slaked  lime  in  powder,  4  hectolitres,  inert  material,  7  hectolitres. 

The  stability  of  the  sulphide  of  lime,  as  measured  by  the  action 
upon  it  of  C02,  depends  largely  upon  the  temperature  at  which  the 
sulphide  is  formed. 

The  energy  of  union  as  between  calcium  sulphide  and  CS2  is  sharper 
and  much  more  complete  when  the  sulphide  is  prepared  from  hot 
lime,  and  is  maintained  at  about  the  temperature  of  75°  F.  Sulphide 
so  made  and  used  is  said  to  have  30  per  cent,  greater  efficiency  ;  and 
by  chilling  the  vessel  the  efficiency  can  be  reduced  to  nil. 

A  very  small  quantity  of  C02  passing  into  a  sulphide  vessel 
materially  decreases  the  efficiency. 

Weldon  mud  is  a  bye  product  from  the  manufacture  of  bleaching 
powder  with  lime  and  air,  and  consists  principally  of  hydrated  oxides 
of  manganese  (Mn02  and  MnO)  and  of  calcium. 

Weldon  mud  will  absorb  about  four  to  five  times  the  H2S  that 
oxide  of  iron  will,  forming  sulphide  of  manganese  and  water. 

Weldon  mud  equals  about  52  per  cent,  water  and  26  per  cent, 
manganese  dioxide,  and  should  remove  28'1  per  cent.  S  first  time,  16*7 
per  cent,  second  time,  5 -8  per  cent,  third  time. 

About  1  per  cent,  of  air  is  considered  best  with  Weldon  mud  when 
it  is  used  for  the  first  removal  of  H2S. 

About  10  to  15  grains  H2S  per  100  cubic  feet  is  contained  in  the  gas 
when  it  reaches  the  check  purifiers,  where  lime  or  Weldon  mud  is 
found  more  active  for  such  small  quantities  than  oxide  of  iron. 
Weldon  mud  with  about  £  per  cent,  of  air  has  continued  active  in  this 
position  for  two  to  three  years,  and  is  said  to  represent  a  labour 
saving  as  against  lime  of  1  to  16  ;  the  pressure  thrown  decreases  with 
time,  whereas  with  lime  and  oxide  it  increases. 

Comparative  quantity  of  oxide  shifted  at  Beckton  per  100,000,000 
cubic  feet  gas  made,  503  cubic  yards  as  against  50  cubic  yards  of 
Weldon  mud ;  this  refers  to  the  material  used  in  the  primary 
elimination  of  H2S. 

In  the  all  lime  purifying  method  about  1J  per  cent,  air  is  about  the 
best  quantity. 

The  use  of  air  greatly  mitigates  the  bad  smells  given  off  by  oxide 
when  it  is  first  removed  from  the  purifiers,  and  doubles  the  length  of 
time  the  purifiers  will  last  without  recharging. 

Air  used  with  lime  purifiers  will  cause  the  sulphur  taken  up  by  the 
lime  to  be  converted  into  free  sulphur  to  the  extent  of  10  per  cent., 
instead  of  being  driven  off  by  the  C02. 

The  use  of  air  (1£  per  cent.)  in  purification  enables  the  oxide  to 
absorb  some  25  per  cent,  sulphur  before  it  need  be  removed  for 
complete  revivification. 

Purifiers  by  the  air  process  have  been  filled  with  oxide,  and  not 
again  discharged  until  the  material  contains  nearly  60  per  cent,  of 
sulphur. 

More  than  3  per  cent,  air  not  only  reduces  the  illuminating  power, 
but  is  inclined  to  cake  the  oxide  and  to  raise  the  temperature  of  the 
material. 

The  admission  of  air  or  oxygen  to  the  purifiers  effects  an  oxidation 


REVIVIFICATION   IN  SITU.  275 

of  the  sulphur  compounds  of  the  lime,  and  sulphur  is  deposited  as 
such  in  the  foul  lime.  (Butterfield.) 

Air  may  be  used  in  a  sulphide  vessel  to  reconvert  a  polysulphide 
into  a  monosulphide,  or  to  render  a  box  sulphided  at  a  low  tempera- 
ture active. 

Steam,  when  used  to  inject  air  into  purifiers,  has  been  found  to 
prevent  the  caking  of  the  oxide ;  it  has  been  suggested  to  introduce 
it  at  the  inlet  to  first  purifier  so  as  to  raise  the  temperature  to  100°. 

Revivification  by  steam  jet  in  situ  may  set  fire  to  the  grids. 

Mr.  Carpenter  admits  1  per  cent,  air  into  the  third  or  fourth 
purifier  and  thus  obtains  the  desired  effect  on  the  ones  required  for  the 
removal  of  the  sulphur  compounds. 

When  air  is  used  (2  per  cent.)  to  aid  purification  in  oxide  vessels 
the  use  of  ammonium  hydrate  (ammoniacal  liquor  4°  Twaddel) 
sprinkled  on  the  oxide  before  use  is  found  to  increase  the  life  of  the 
charge  from  80  to  100  per  cent.  (R.  G.  Shadbolt.) 

Two  and  a  half  per  cent,  air  used  in  purification  lowered  17'3 
candle  gas  to  13*45  candles. 

Three  per  cent,  air  used  in  purification  lowered  17*3  candle  gas  to 
13-04  candles. 

Five  per  cent,  air  used  in  purification  lowered  17'3  candle  gas  to 
10-59  candles. 

Seventeen  and  a  half  per  cent,  air  used  in  purification  lowered 
17'3  candle  gas  to  1-0  candle. 

An  arrangement  for  pumping  into  the  gas  at  the  inlet  of  the  puri- 
fiers 3  per  cent,  air  carburetted  with  tar  of  specific  gravity  1-196,  kept 
at  a  temperature  of  170°  by  a  steam  coil,  was  patented  by  Mr.  Hawkins, 
to  remove  the  loss  of  illuminating  power  occasioned  by  the  use  of 
such  a  large  quantity  of  air.  The  specific  gravity  of  the  tar  after 
leaving  the  carburettor  was  1'218.  The  only  objection  appeared  to 
be  the  possibility  of  a  deposit  of  napthalene  in  the  mains  during 
severe  winter  weather.  The  illuminating  power  appears  to  have  been 
maintained  throughout  the  district. 

The  quantity  of  air  necessary,  according  to  theory,  for  continuous 
revivification  of  oxide  is  2£  per  cent,  air  for  1  per  cent.  H2S.  A 
slight  margin  in  excess  is,  however,  necessary  in  practice  for  safety. 

It  is  said  that  the  higher  temperature  in  a  purifier,  due  to  the 
increased  chemical  activity  of  the  purifying  material  when  air  is  used, 
prevents  the  deposition  of  some  of  the  valuable  hydrocarbons,  which 
in  the  ordinary  way  would  be  condensed  ;  the  napthalene  on  the 
under  side  of  a  purifier  cover  in  winter  clearly  showing  that  such  a 
deposition  will  take  place. 

Advantages  claimed  for  the  use  of  0  with  oxide  of  iron  purifi- 
cation are — Almost  complete  revivification  of  oxide  in  situ ; 
increased  illuminating  power ;  greatly  augmented  percentage  of 
sulphur  in  spent  oxide,  and  consequent  higher  market  value  ;  the 
purification  more  efficiently  conducted,  with  half  the  purifying 
space  and  two-thirds  of  the  material ;  a  corresponding  saving  in 
capital  and  labour. 

Lime  can  be  wholly  used  in  conjunction  with  oxygen  for  the  puri- 
fication of  gas.  By  the  regulation  of  quantity  of  0  to  quantities 

T2 


276  GAS  ENGINEER'S  POCKET-BOOK. 

of  impurities  sulphur  compounds  can  be  removed.  Purifying  space 
and  plant  now  required  for  lime  reduced  by  more  than  one-half,  lime 
used  by  nearly  one-half,  and  labour  in  proportion.  Auxiliary  oxide 
of  iron  purifiers  are  rendered  unnecessary.  Very  considerable  saving 
is  caused  by  improvement  in  illuminating  power.  Sulphur  deposited 
possibly  recoverable.  (W.  A.  Mel.  Valon.) 

With  oxygen  and  lime  only  and  average  of  620  grains  S  per  100 
cubic  feet  at  inlet,  2  cubic  yards  lime  per  million  cubic  feet  kept 
sulphur  compounds  down  to  an  average  of  6  to  8  grains  per  100  cubic 
feet,  and  the  illuminating  power  maintained  at  16*5  candles.  (W.  A. 
Mel.  Valon.) 

Proportion  of  Oxygen  Required  for  Purification. 

0*1  per  cent.,  by  volume  of  oxygen  for  every  100  grains,  H2S  per  100 
cubic  feet  removes  all  the  H2S  and  C02,  and  reduces  the  sulphur 
compound  to  7  or  8  grains  per  100  cubic  feet  of  purified  gas. 

One  foot  pure  0  is  sufficient  to  remove  1 ,000  grains  H2S  in  the  crude 
gas;  or  *1  per  cent,  by  volume  of  0  per  100  grains  H0$  per  100  cubic 
feet. 

One  half  the  volume  of  H2S  in  the  gas  is  required  of  oxygen  to 
revivify  the  oxide  in  situ. 

No  increase  in  heat  is  found  in  the  oxide  when  using  0. 

When  oxygen  is  used  with  lime  purifiers  the  H2S  first  taken  up  by 
the  lime  is  not  expelled  again  by  the  C02,  but  the  S  is  thrown  down 
in  the  form  of  grains  of  pure  sulphur,  leaving  the  lime  as  active  for 
the  C0a  as  if  no  sulphur  had  been  retained. 

To  Prepare  Oxygen. 

When  air  is  compressed  over  water,  the  components  of  the  atmos- 
phere are  taken  up  in  direct  ratio  of  the  pressures  employed.  On 
releasing  the  pressure,  there  is  proportionally  more  oxygen  in  the 
evolved  gases ;  by  repeating  the  process  eight  times  97-3  per  cent, 
oxygen  can  be  obtained. 

Composition  after  Successive  Pressures. 
N.     79     66-67     52-5     37'5     25-0     15'0       9-0      5-0      2-7 
O.      21     33-33     47-5     62'5     75'0     85'0     91-0     95-0     97'3 

For  a  material  to  revivify  in  situ  it  must  have  a  strong  affinity  for 
O,  so  as  to  combine  with  it  energetically  as  it  passes  through  the  gas. 

Cyanogen. 

It  would  appear  from  the  reactions  expressing  these  changes  that 
the  cyanogen  exists  in  coal  gas  exclusively  in  the  forms  of  cyanide 
and  sulphocyanide  of  ammonium. 

Fsrj-ocyanide  of  iron  is  formed  if  cyanogen  and  ammonia  in  only 
small  traces  are  allowed  to  get  to  the  oxide  purifiers  ;  this  reduces 
the  activity  of  the  oxide  for  the  removal  of  H2S. 

A  large  portion  of  the  cyanogen  combines  with  the  iron  in  the 
purifiers  to  form  a  ferrocyanide  or  Prussian  blue,  but  the  quantity  is 
reduced  if  first  passed  through  lime. 


CYANOGEN.  277 

Average  per  cent,  of  sulphocyanic  acid,  ammonia,  and  potassium 
ferrocyanide  obtained  from  12  German  gasworks — 

HCNS  =  2-62,    NH3=l-87,    K4FeCy«+ 3aq=5'l. 

One  ton  of  coal  by  the  Glaus  ammonia  process  yields  J  Ib.  Prussian 
blue  and  If  Ibs.  copper  sulphocyanide. 

Leybold  found  cyanogen  equal  to  about  4  Ibs.  of  ferrocyanide  in 
10,000  cubic  feet  of  gas,  of  which  nearly  95  per  cent,  remained  in  the 
scrubbed  gas.  When  lime  is  used  for  purifying  the  gas,  the  cyanogen 
is  lost ;  and  if  iron  be  used  the  cyanogen  is  converted  largely  into 
sulphocyanide  in  which  form  it  is  not  so  readily  available.  But  when 
the  gas  after  it  leaves  the  scrubber  is  brought  into  intimate  contact 
with  precipitated  oxide  of  iron,  suspended  in  an  alkaline  solution,  as 
recommended  by  Knublauch,  the  cyanogen  is  easily  obtained  as 
ferrocyanide,  almost  free  from  sulphocyanide. 

Removal  of  the  Cyanogen  Compounds. 

To  ensure  material  rich  in  Prussian  blue  keep  the  stuff  very  moist 
at  a  low  temperature,  have  a  large  purifying  surface  and  long  con- 
tact. When  revivifying  in  the  open  air  spread  the  material  in  very 
thin  layers  kept  quite  moist  ;  but  if  in  situ  inject  cold  air  saturated 
with  moisture  at  great  speed.  In  the  case  of  continuous  revivifica- 
tion the  opposite  process  must  be  adopted,  owing  to  the  presence  of 
less  sulphide  of  iron  in  the  purifiers. 

Oil  gas  tar  will  remain  on  the  sides  of  purifier  covers,  also 
petroleum  oil. 

Composition  of  Purified  Illuminating  Gas. 


COMMON  GAS. 

Authority. 

Permanent 
Gases, 
H,  CO,  He,  &c. 

Illuminating 
Compounds  or 
Light  Bearers. 

Impurities, 

NH;,C&C.' 

Bunsen         .        .        .  ' 
Letheby  (12  candle  gas) 
Odling 
,j         .        .        . 

;,            .                   .                   .               '    • 
,,                     .                   .                    . 
„             .                   .                   .        ?         . 

87-12 
93-00 
96-42 
93-92 
89-83 
90-03 
96-01 

6-56 
3-80 
3-05 
3-56 
3-67 
3-63 
3-53 

6-42 
3.20 
0-53 
2-53 
6-50 
0-40 
0-46 

CANNEL  GAS. 

Letheby  (22  candle  gas) 
Odling     .... 
Two  analyses  of  water  \ 
gas  as  sold  in  New  York  / 

84-05 
88-00 
/  78-90 
\SM6 

13-00 
10-81 
15-29 
15-29 

2-50 
1-19 
4-8 
3-5 

278  GAS  ENGINEER'S  POCKET-BOO^. 

Composition  of  Purified  Coal  Gas. 
(Professor  V.  B.  Lewes,  1890.) 

Per  Cent. 

H 47-9 

Illuminants,  ethylene  series  .         .     .  3*5 

..         benzene      „    .        .        .  0'9 

.,         methane      ...        .     .  7'9 

Methane      .        .        .    "    .        .        .  33-3 

CO 6-0 

C03 0-0 

O 0-5 

N 0-0 

100-0 

5,000  cubic  feet  lime  will  absorb  about  5  tons  H3S.     This  sulphided 
lime  will  absorb  about  3  tons  CSa. 


STORING   GAS. 


GASHOLDERS  (CARE  OP). 

It  takes  a  considerable  time  for  the  diffusion  of  gases  of  different 
densities  even  when  of  great  difference  of  density,  when  in  conditions 
usual  in  gasholders. 

Diffusion  of  Gases, 

The  velocity  of  diffusion  of  different  gases  is  inversely  propor- 
tional to  the  square  roots  of  their  densities. 


Density.  Air=l 

1 
(V/Density. 

Velocity  of 
diffusion.  Air  =  1 

Hydrogen    . 
Nitrogen.        .        .     . 
Oxygen 
Carbon  dioxide        .     . 

0-06926 
0-97130 
1-10560 
1-52900 

3-7790 
1-0150 
0-9510 
0-8087 

3-830 
1-014 
0-949 

0-812 

(Graham.) 


Gases  of  different  specific  gravity  will  mix  in  time,  but,  owing  to  the 
temperature  of  either  the  incoming  gas  or  the  heat  of  that  in  the 
holder,  the  mixing  may  take  a  considerable  time,  the  warmer  gas 
keeping  to  the  top  of  the  holder.  From  the  heat  of  the  sun,  the 
crown  of  a  gasholder  becomes  so  hot  that  it  cannot  be  touched  with 
the  hand,  being  at  least  from  113°  to  122°  F.  (W.  Ley  bold.) 

The  contact  of  ordinary  coal  gas  with  water  is  found  to  cause  a 
rapid  diminution  in  illuminating  power.  (Irwin.) 

Carburetted  water  gas  stored  in  a  holder  for  17  days,  lost  1£  candles 
in  value  at  Blackburn. 

Napthalene  in  gas  holder  inlet  pipes  is  usually  found  to  commence 
at  and  continue  below  the  level  of  the  surrounding  water. 

Do  not  lower  a  telescopic  holder  in  a  gale  so  as  to  leave  the  upper 
lift  only  exposed.  As  the  centre  of  gravity  is  very  near  the  crown, 
it  is  the  more  easily  overturned,  while,  if  the  second  lift  is  out  of  the 
water  its  weight  brings  the  centre  of  gravity  considerably  lower. 

Frost  has  been  known  to  cause  the  sides  of  brick  tanks  to  bulge 
inwards  and  prevent  the  holder  moving  up  and  down. 


Fainting  Notes. 

Gasholders  should  be  first  made  clean  by  scrubbing  and  brushing 
with  wire  brushes,  any  bubbles  of  the  old  paint  being  scraped  off 
with  an  old  file  sharpened  at  the  edge. 

Before  painting  a  holder  well  scrape  the  old  paint  and  remove  old 
blisters  and  scales  which  might  cause  a  lodgment  of  water  and 
consequent  oxidation  of  the  plates. 


280  GAS  ENGINEER'S  POCKET-BOOK. 

With  paint,  too  much  oxide  is  not  good  for  the  oil  which  is  then 
oxidized  too  quickly  and  rendered  natureless,  so  that  the  paint 
eventually  powders  off.  (Wood.) 

A  Coating  for  Gasholders. —  Mix  and  raise  to  boiling  point,  1  gallon 
of  tar  and  £  Ib.  asphalte,  then  add  1  pint  coal  naptha  and  £  Ib. 
tallow.  Use  warm. 

The  outer  surface  of  gasholders  may  be  covered  with  paint,  or  tar 
mixed  with  tallow,  and  it  has  been  proposed  to  do  this  in  the  spring 
and  also  autumn  each  year. 

Oil  gas  tar  is  an  excellent  paint  for  gasholders. 

Tar  for  painting  should  only  be  raised  sufficiently  high  in  tempera- 
ture to  drive  off  all  the  water,  should  be  fluid  when  cold,  too'thick 
for  use,  and  can  be  thinned  with  turpentine,  1  turps,  to  4  tar ;  1  gallon 
will  cover  64  square  yards  of  metallic  surface. 

Bed  lead  sets  harder  and  sooner  than  white  lead. 

Contents  of  crown,  to  find  :  Square  the  radius  of  the  holder,  multiply 
this  square  by  3  ;  to  the  product  add  the  square  of  the  rise  and  multiply 
by  -5236. 

In  filling  the  holder  with  gas  it  is  best  to  use  a  high-class  coal,  and 
so  compensate  for  the  air  in  crown,  as  it  is  difficult  to  expel  the  latter. 


DISTRIBUTING   GAS.  281 

DISTRIBUTION. 
Mains.     Services.    Meters. 

Quantity  of  gas,  in  cubic  feet,  discharged  per  hour  by  any  main  can 
be  found  as  follows  : — 


Where— 

h  =  pressure  of  gas  in  inches  of  water. 
d   =  diameter  of  pipes  in  inches. 
S   =  specific  gravity  of  gas  (air  =  1) 
L  =  length  of  pipe  in  yards. 

(Dr.  Pole.) 

Another  rule  is — 


(Molesworth's  Pocket  Book.) 
And  another  is — 

x=  1,000  ^/pL 

(Spon's  Pocket  Book.) 
The  first  is  the  most  correct. 


Flow  of  Air  in  Pipes.    (Hawksley.) 
Velocity  in  feet  per  second  = 

head  in  inches  of  water  x  diameter  of  pipe  in  feet 
length  of  pipe  in  feet 

Head  in  inches  of  water  =  length  of  pipe  in  feet  X  velocity 
Io6,800  diameter  of  pipe  in  feet 

Contents  of  pipe  =  square  of  diameter  X  '7854  x  length  ; 
contents  in  cubic  feet  X  6-26  =  gallons. 

Weight  of  cast  iron  pipe  =  K  (D2 — d2).     K  =  (for  cast  iron)  2-5. 

Flange  equals,  say.  1  foot  of  pipe  in  weight. 

In  a  24-inch  pipe  delivering  240.000  cubic  feet  per  hour  into  one 
18-inch  pipe  and  two  14-inch  pipes  at  a  distance  of  about  2,000  yards 

47        20 
the  pressure  was  reduced  from  — -  to  — 


282 


GAS   ENGINEERS    POCKET-BOOK. 


Capacity  of  pipes. 
500  750  1000 


1250  1500 


16,000 


15,000 


14,000 


DELIVERING   POWER   OP   PIPES. 
Capacity  of  pipes. 


283 


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250      500      750     1000     1250 
Length  in  yards. 


i75o 


284 


GAS   ENGINEER'S   POCKET-BOOK. 


Capacity  of  pipes. 
250      500     750     1000     1250    1500     1750      2000 


4" 

2" 
4" 


10. 


tr  I 

i"  ..  ?? 


LEAD   REQUIRED    FOR   JOINTING. 


285 


Relative  Carrying  Capacity  of  Gas  Pipes. 

(Compiled  from  Tables  by  Norwalk  Iron  Co.,  U.S.A.) 


Inches. 

24  =  1-00     . 
12  =  0-17 
10  =  0-10     . 

8  =  0-06 

7  =  0-04     . 

6  =  0-03 

5  =  0-0189 
4J  =  0-0141  . 

4  =  0-0102 
3£  =  0-0069  . 

3  =  0-0045 
2i  =  0-002835 

2  =  0-001485   . 
IA  =  0-000810 
IA  =  0-000450   . 

1  =  0-000225 


Comparative  Areas. 

.  1-00 

.     .  0-25 

.  0-175 

.     .  0-111 

.  0-085 

.     .  0-0625 

.  0-0434 

.     .  0-0351 

.  0-0278 

.  0-0212 

.  0-0156 

.     .  0-0108 

.  0-0069 

.     .  0-0039 

.  0-00272 

.  0-00173 


High  Pressure  Gas  Delivery.     (F.  H.  Oliphant.) 

Cubic  feet  per  hour  =  42  a  .1 1— 

P  and  p  are  gauge  pressures  at  intake  and  discharge  ends  of  pipe 
plus  15  Ibs.,  1  is  length  in  yards,  a  for  different  sizes  of  pipes  is  : — 


Diameter 

Diameter 

Diameter 

Diameter 

inside. 

a 

inside. 

a 

inside. 

outside. 

Cl 

0-25 

0-0317 

4 

34-1 

14-25 

15 

863 

0-50 

0-1810 

5 

60 

15-25 

16 

1025 

0-75 

0-5012 

6 

96 

17-25 

18 

1410 

1-0 

1-0000 

8 

198 

19-25 

20 

1860 

Rivetted  or  cast  iron  pipes. 

1-5 

2-9300 

10 

350 

20 

2055 

2-0 

5-9200 

12 

556 

24 

3285 

2-5 

10-3700 

16 

1160 

30 

5830 

3-0 

16-5 

18 

1570 

36 

9330 

286 


GAS  ENGINEER'S  POCKET-BOOK. 


,...  GO- 

Weight  SO  Ibs.  each. 


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Weight-  /20/6s.each. 


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DIMENSIONS   OF   PIPES. 


287 


288 


GAS  ENGINEER'S  POCKET-BOOK. 


3 

?, 
Jp 

H 

J! 


Mains. 

48-inch  Socket  joint  requires  90  Ibs.  lead  and  8  yards  yarn. 
1H      „     „ 
72     „      „  6       „ 

10S       ?f       „ 

60     „      ,.  5       „        „ 

90          ,,  ., 

48  „  „  4      „        „ 

72  „  „ 

32  „  „ 

18-2  „  ,. 

14-9  „  ,. 

11-5  „  „ 

10-4  „  „ 

8-2  „  „ 

7-7  „  „ 

6'5  „  ., 

5  „  „ 

4  „  „ 

2'6  „  „ 

Flange  joints  made  with  wrought-iron  ring  J-inch  thick  placed 
between  flanges  and  bolted  up,  afterwards  run  with  lead  and  set  up. 

Yarn  weighs  1  qr.  23£  Ibs.  per  250  yards  equals  1  coil. 

All  mains  above  6  inches  diameter  should  be  cast  vertical  so  that  a 
few  inches  at  the  end  may  be  cut  off  and  any  porous  part  removed. 

Cast  iron  pipes  should  be  of  close  grain  and  equal  thickness 
throughout.  This  can  be  found  by  rolling  them  on  two  rails  or  metal 
edges  and  noting  if  there  be  a  heavy  side  by  the  pipes  always  rolling 
to  one  position,  and  they  should  emit  a  bell-like  sound  when  tapped 
with  a  hammer. 

They  should  be  tested  to  from  90  to  130  Ibs.  per  square  inch,  and 
tapped  while  under  pressure  ;  if  water  is  seen  oozing  from  cracks  or 
flaws  the  pipes  should  be  rejected. 

Weight  in  Founds  and  Depth  of  Lead  for  Ordinary  Lead  Joints. 


48 

„      Flange 

36 

.,      Socket     . 

36 

„      Flange 

30 

„      Socket 

30 
24 

„      Flange 
,      Socket     , 

24 

Flange     , 

18 

5 

Socket      . 

12 

5 

J>                   V 

11 

1 

«               J 

10 

) 

9 

. 

? 

8 

J 

5 

J 

7 

J 

. 

, 

6 

5>                     » 

» 

5 

»                   5 

J 

4 

5>                   > 

3 

>J                   J>                 » 

Diameter  of 
Pipe. 

Weight  of 
Lead. 

Depth  of 
Lead. 

Diameter  of 
Pipe. 

Weight  of 
Lead. 

Depth  of 
Lead. 

Inches. 

Lbs. 

Inches. 

Inches. 

Lbs. 

Inches. 

2 

If 

}i 

12 

18i 

2f 

3 

2f 

If 

13 

21 

2f 

4 

4 

If 

14 

23J 

2| 

5 

5i 

1* 

15 

26 

2* 

6 

7 

2 

16 

28£ 

2i 

7 

8| 

2 

17 

31 

2i 

8 
9 

10* 
12* 

2* 
2| 

18 
19 

32£ 
34 

2f 

2| 

10 

1H 

2i 

20 

35£ 

2§ 

11 

16i 

2* 

24 

48 

3 

For  pipes  up  to  8  inches  in  diameter  the  lead  is  taken  at  §  inch 
thick,  and  for  pipes  from  9  inches  diameter  upwards  the  lead  is  taken 
at  inch  thick. 


PIPE    JOINTS. 


289 


Dimensions  of  Cast  Iron  Pipe  Flanges  to  bear  75  Ibs.  Pressure. 
(Briggg.) 


lit 

Thickness  1 
of  Body.  1 

Thickness  1 
of  Boss. 

S- 

tcj 

r 

Thickness  I 
of  Flange  1 
Finished.  J 

i!.c 

£33 

ofe  o 

£-0* 

Diajneterofl 
Bolt  Holes.  1 

Outside  1 
Diameter  1 
of  Flange.  1 

Diameter  1 
of  Bolts 
Inside. 

Number  of  1 
Bolts 

Diameter  j 
of  Bolts.  | 

3 

•328 

•40 

1-25 

•50 

•56 

•55 

6* 

&i 

4 

^ 

H 

•3U 

•42 

1-2S 

•51 

•57 

•61 

4 

4 

ft 

4 

•354 

.43 

1-30 

•53 

•59 

•61 

8 

5 

I 

5 

•380 

•46 

1-35 

•56 

•63 

•61 

9 

7* 

6 

ft 

6 

•406 

•49 

1-40 

•60 

•67 

•68 

10j 

6 

I 

8 

•453 

•55 

1-50 

•66 

•74 

•68 

12* 

]OA 

8 

# 

10 

•510 

•61 

1-60 

•73 

•81 

•81 

15 

13-5- 

10 

1 

12 

•563 

•67 

1-70 

•80 

•89 

•93 

17f 

15ft 

10 

i 

16 

•6(57 

•79 

1-90 

•93 

1-01 

•93 

22 

19* 

14 

i 

DLme:i3lons  of  Socket  Joints.     (Unwin.) 


Where  t  =  thick  n-jss  of:  pipe  and  d  =  diameter  of  pipe. 


*  to  0-025^  +  0-6 
=0'045fl?  +  0-8 
=0'01rZ  +  -25  to  O'Ol^  +  '375 


I  =  0-09d  +  2|  to  0-ld  +  3 
and  J  = 


Thickness  of  Pipes  for  90  Ibs.  Pressure  per  Square  Inch  up  to  20 
Inches  Diameter,  and  up  to  75  Ibs.  Pressure  per  Square  Inch 
up  to  60  Inches  Diameter. 


Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Diameter      of 

Pipe    . 

4 

8 

12 

16 

20 

24 

30 

36 

42 

48 

54 

60 

Thickness  .     . 

f 

7 
16 

i 

0 

Ta 

i 

}£ 

lo- 

t 

K 

i 

tt 

1 

G.B. 


290 


GAS  ENGINEER'S  POCKET-BOOK. 


Dimensions  of  Turned  and  Bored  Pipes  in  Inches. 


Dia- 
meter 
of 
Pipe. 

Thick- 
ness. 

Depth 
of 
Socket. 

Thick- 
ness 
of 
Rim. 

Thick- 
ness 
of 

Socket. 

Dia- 
meter 
of 
Pipe. 

Thick- 
ness. 

Depth 
of 
Socket. 

Thick- 
ness 
of 
Rim. 

Thick- 
ness 
of 
Socket. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

2 

* 

3 

i 

A 

11 

$| 

m 

3 

I 

3f 

-1 

1 

12 

4J 

l« 

4 

& 

4 

H 

13 

I 

4i 

11 

TS 

5 

6 

f 

4 
4* 

if 
H 

? 

14 
15 

I 

52 

If 

2 

l"5 

7 

* 

I* 

1 

16 

1 

5 

2 

1 

8 

* 

4* 

M 

g 

17 

I 

5£ 

2* 

IJL 

9 

10 

i 

if 

if 

18 
20 

tt 

y 

4 

24 

if 

THICKNESS  or 
RIM 


THICKNESS    or    SOCKKT 


THICKNESS 


Weight  of  Socket 


2    inches  diameter  = 

4-54  It 

2*       »                       = 

6-64    „ 

3 

:= 

11-2 

4 

: 

— 

14-45 

5     : 

— 

21-0 

6 

, 

— 

24-8 

7 

— 

33-0 

8 

^s 

37-36 

9 

— 

41-7 

10 

—  . 

52-30 

11 

I 

= 

57-27 

of  Cast  Iron  Pipes. 

12  inches  diameter  =    90-54  Ibs 

15       „  =  112-36    „ 

18 

20 

21 

24 

30 

36 


42 

48 


=  147-64 
=  179-0 

=  188-0 
=  250-0 
=  346-0 
=  480-0 
=  589-0 
=  707-0 


Weight  of  socket  equals  '9  foot  of  pipe. 

Weight  of  socket  turned  and  bored  and  thickened  spigot  equal  to 
1*1  feet  of  pipe. 

Weight  of  flange  equals  1  foot  of  pipe. 

Depth  of  Socket.  Jointing  Space. 

2  inches  and  3    inches  diameter      3    inches        f  inch 
4      „       to     8        „  „  4        „ 

9      »       „      20      „  .,  4*      „ 

-  21       „        „      30       „  .,  5        „ 

Above  „       „  ,  6 


LAYING    MAINS.  291 


To  Test  Mains  in  District. 

The  portion  of  main  to  be  tested  must  be  isolated  by  bagging  or 
water-logging,  and  a  pressure  put  upon  it  by  a  motive  power  meter  or 
small  holder.  The  quantity  of  gas  or  air  required  to  keep  up  the 
initial  pressure  equals  the  loss  through  leakage. 

Coating  for  Pipes. 

A  composition  of  Burgundy  pitch,  oil,  resin,  and  gas  tar  is  made 
up  in  a  bath,  into  which  the  pipes  are  lowered,  where  they  remain 
until  they  attain  the  heat  of  this  composition,  which  is  about  142°  F. 
They  are  then  taken  out  and  placed  in  such  a  position  as  to  allow  all 
unnecessary  matter  to  run  off. 

To  find  the  force  tending  to  dive  off  a  bend  on  a  line  of  pipes  sub- 
jected to  internal  pressure.  The  resultant  force  in  the  straight  pipe 
on  either  side  of  the  bend  being  equal  to  the  area,  A,  of  the  pipe,  X  the 
intensity,^?,  of  the  pressure,  and  acting  axially.  The  resultant  of  these 

two  forces  is  A  X  p  X  2  sin.  _.  where  0  is  the  angle  subtended  by  the 

bend. 

Pipes  up  to  9  inches  diameter  should  never  have  less  than  1  foot 
9  inches  of  ground  above  them  ;  above  this  size  the  depth  should  be 
increased  at  least  6  inches. 

Pipes  laid  in  clinkers  and  ashes  will,  after  a  time,  part  with  a  con- 
siderable portion  of  their  iron,  leaving  a  substance  which  can  be 
easily  scraped  with  a  penknife.  Clay,  however,  forms  a  most  excel- 
lent soil  for  pipe  laying.  It  has  been  noticed  that  gas  pipes  are 
attacked  at  points  where  electricity  leaves  them  when  in  proximity 
to  electric  tramways,  and  not  where  the  current  penetrates  them. 

Pipes  with  rough  interior  surface  have  been  known  to  reduce 
delivery  of  liquids  33  per  cent,  from  that  delivered  when  smooth. 
(Fitzgerald.) 

Never  drill  a  larger  hole  than  |  inch  in  a  2-inch  main.  Never  drill 
a  larger  hole  than  1  inch  in  a  3-inch  main. 

In  small  mains  a  f-inch  bend  may  be  fixed  to  a  reducing  socket  and 
a  1-inch  service  carried  from  that  without  materially  reducing  the 
quantity  of  gas  which  may  be  passed,  and  at  the  same  time  this 
method  renders  a  small  main  less  liable  to  leak. 

Allow  a  fall  of  3  inches  per  100  yards  in  street  mains  ;  or  better, 
mains  should  have  a  fall  of  about  1  inch  in  20  yards  as  a  minimum. 

Lay  mains  with  a  fall  of  not  less  than  |  to  1  inch  to  every  9  feet 
length. 

Where  pipes  have  to  be  carried  across  exposed  positions,  as  when 
they  are  slung  or  fixed  outside  bridges,  &c.,  they  should  be  covered 
with  felt  or  other  non-conducting  material. 

Sleepers  may  be  used  with  advantage  under  mains  when  laying  in 
bad  and  soft  ground. 

The  ground  should  be  well  consolidated  under  mains  to  prevent 
subsequent  uneven  settlement. 

U2 


292  GAS  ENGINEER'S  POCKET-BOOK. 

To  find  a  leak  try  with  a  pricking  bar  near  each  socket,  and  to  the 
full  depth  of  the  bottom  of  the  main  ;  and  if  gas  be  present,  even  in  a 
very  small  quantity,  it  will  burn  with  a  more  or  less  blue  light. 

A  broken  pipe  may  be  temporarily  bandaged  with  stout  calico  well 
plastered  with  white  and  red  lead,  until  a  new  pipe  can  be  laid. 

When  lead  pipes  are  used  for  services  they  must  be  supported  their 
entire  length,  to  prevent  sagging  and  subsequent  accumulation  of 
water  and  stoppage  of  supply. 

Service  pipes  may  be  made  to  last  longer  by  receiving  one  or  two 
coats  of  good  oxide  paint  or  hot.tar. 

It  is  better  to  use  soap  and  water  (soft  soap  is  best)  than  to 
employ  a  light  to  try  if  a  joint  in  a  main  be  tight  or  no. 

Millboard  joints  should  be  well  soaked  in  water  and  painted  both 
sides  with  red  and  white  lead. 

Gas  valves  should  stand  5  Ibs.  pressure  on  side  opposite  springs. 

One  or  more  trunk  mains  should  always  come  from  the  works  and 
terminate  at  central  points,  whence  the  distributing  pipes  may  start. 

A  piece  of  tallow  in  the  "  gate  "  of  the  joint  when  running  with 
lead  prevents  blowing  even  if  the  yarn  or  pipe  be  wet. 

If  too  much  lead  is  left  on  the  outside  of  a  joint  the  caulking  up 
may  split  the  socket. 

The  yarn  should  not  occupy  more  than  half  the  depth  of  the 
socket  when  driven  hard  in  with  the  tool. 

Ordinary  putty  may  be  used  instead  of  lead  for  temporary  joints 
after  the  yarn  is  well  rammed  in. 

It  is  the  return  currents  of  electricity  which  are  responsible  for 
the  electrolytic  action  ;  and  it  seems  to  have  the  same  effect  on 
galvanised,  tar  coated,  or  so-called  "  rustless  "  pipes. 


Cement  for  the  Repair  of  Leaks  in  Gas  and  Other  Pipes. 

To  5  parts  of  Paris  white  add  5  parts  of  yellow  ochre,  10  parts 
of  litharge,  5  parts  of  red  lead,  and  4  parts  of  black  oxide  of 
manganese.  The  constituents  should  be  well  mixed  and  a  small 
quantity  of  asbestos  arid  boiled  oil  added.  The  cement  hardens 
in  from  two  to  five  hours  after  application  to  the  leaks,  and  exposes 
no  fresh  holes  on  drying.  As  the  use  of  the  cement  does  not  involve 
the  removal  of  the  *pipes  it  is  especially  adapted  for  the  repair  of 
those  which  are  difficult  to  get  at. 

In  South  Boston,  U.S.A.,  all  mains  are  laid  with  cement  joints, 
made  by  using  two  hard-twisted  rolls  of  lath-yarn,  and  a  mixture  of 
2  parts  of  common  cement,  one  part  Portland  cement,  and  one  part 
sand. 

Turned  and  bored  pipes  are  cheaper  to  lay,  but  do  not  allow  of  any 
settlement,  and  consequently  break  easier  than  the  open  lead  joint. 

Leakage  in  cubic  feet  per  hour  through  holes  in  plates 

*J pressure  in  inches  X  diameter  of  hole  in  inches3  X  1200. 

(F.  S.  Cripps.) 


RACK   AND   PINION   GAS   VALVES.  293 

Dimensions  of  Rack  and  Pinion  Gas  Valves. 


Diameter 
of 
Valve. 

Diameter 
of 
Flanges. 

Diameter  of 
Circle 
through 
centre  of 
Bolt  Holes. 

Length 
from  face 
to  face 
of  Flanges. 

Number 
of 
Bolts. 

Diameter 
of 
Bolt  Holes. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

2 

6^ 

5i 

8i 

4 

| 

3 

8£ 

4 

a 

4 

10 

82 

111 

4 

| 

5 

10J 

9 

Hi 

4 

1 

6 

12 

10 

HI 

4 

| 

7 

14^ 

12 

llf 

6 

8 

15i 

13 

6 

9 

17 

Mi 

13i 

6 

10 

18 

16J 

13| 

6 

12 

20J 

17 

16 

6 

i 

14 

22 

19 

16i 

6 

j. 

15 

23 

20 

17 

6 

1| 

16 

24i 

21 

18 

6 

H 

18 

26^ 

23 

18 

6 

H 

20 

29 

25 

20 

8 

If 

21 

30 

26^ 

20 

8 

H 

22 

31 

27 

20 

8 

24 

33 

29J 

20 

8 

1* 

26 

35 

32i 

20 

8 

27 

36 

32£ 

20 

8 

11 

30 

39 

35| 

22 

10 

1* 

36 

46 

42J 

23 

12 

H 

48 

58 

54J     ^ 

31 

16 

H 

Notes  on  Dr.  Pole's  Formula  by  F.  S.  Cripps. 

Let  Q  =  the  discharge  of  gas  in  cubic  feet  per  hour. 
d  =  the  diameter  of  pipe  in  inches. 
p  =  pressure  of  gas  in  inches  of  water. 
s  =  specific  gravity  of  gas,  air  being  1. 
I  —  length  of  pipe  in  yards. 


Then  Q  = 


294  GAS  ENGINEER'S  POCKET  BOOK. 

(1 350)2  d*p 


_ 


From  the  above  it  is  apparent  that,  other  things  being  equal— 


Q  varies  directly  as 


ii     inversely,, 

inversely 


d  varies  directly 


p  varies  directly  as  Q2 


»» 


I  varies  directly    „  p 


n 


„    inversely  „ 
„     inversely , 

s  varies  directly   as  p 
„     inversely  „  Q2 

A  consideration,  of  the  foregoing  gives  rise  to  the  following  axioms 
or  rules ; 

Quantity — Pres  sure. 

(1)  Double  the  quantity  requires  four  times  the  pressure. 
Or,  four  times  the  pressure  will  pass  double  the  quantity. 

(2)  Half  the  quantity  requires  one-fourth  the  pressure. 

Or,  one-fourth  the  pressure  is  sufficient  for  half  the  quantity. 

Quantity— Length. 

(3)  Double  the  quantity  can  be  discharged  through  one-fourth  the 

length. 
Or,  one-fourth  the  length  will  allow  of  double  the  discharge. 

(4)  Half  the  quantity  can  be  discharged  through  four  times  the 

length. 
Or,  four  times  the  length  reduces  the  discharge  one-half. 

Quantity— Diameter. 

(5)  32  times  the  quantity  requires  a  pipe  four  times  the  diameter. 
Or,  a  pipe  four  times  the  diameter  will  pass  32  times  as  much 

gas. 

(6)  A  pipe  one-fourth  the  diameter  will  pass  l-32nd  of  the  quantity. 
Or,  l-32nd  of  the  quantity  can  be  passed  by  a  pipe  one-fourth 

the  diameter. 

Quantity — Specific  Gravity. 

(7)  The  specific  gravity  stands  in  just  the  same  relation  to  the 

volume  as  the  length  does  (see  Axioms  3  and  4). 

Pressure— Length. 

(8)  If  the  pressure  is  doubled  the  length  may  be  doubled. 

And,  conversely,  if  the  length  be  doubled  the  pressure  must  be 
doubled. 


CRTPPS  ON  POLE'S  FORMULA.  295 

(9)  If  the  pressure  be  halved  the  length  may  be  halved. 

And,  conversely,  if  the  length  be  halved  the  pressure  must  be 

halved. 
From  Axioms  8  and  9  it  is  evident  that — 

(10)  The  pressure  required  to  pass  a  given  quantity  of  gas  varies 

exactly  as  the  length  of  the  pipe. 

Pressure — Specific  Gravity. 

(11)  The  pressure  required  to  pass  a  given  quantity  or  gas  also 

varies  exactly  as  the  specific  gravity  of  the  gas.  Hence  if. 
the  specific  gravity  of  the  gas  were  doubled,  double  the 
pressure  would  be  required. 

Pressure — Diameter. 

(12)  l-32nd  part  of  the  pressure  is  sufficient  if  the  diameter  be 

doubled  ;  or,  in  other  words,  if  you  double  the  diameter  you 
only  require  l-32nd  of  the  pressure  to  pass  the  same 
quantity  of  gas. 

(13)  If  you  halve  the  diameter,  32  times  the  pressure  is  required. 
And,  conversely,  if  you  increase  the  pressure  32  times,  the 

diameter  can  be  halved. 

Length— Diameter. 

(14)  The  length  can  be  increased  32  times  if  the  diameter  be 

doubled. 

And,  conversely,  if  the  diameter  is  doubled,  the  length  can  be 
increased  32  times  and  pass  the  same  quantity  of  gas. 

(15)  If  the  diameter  be  halved  the  length   must  be  reduced  to 

l-32nd  to  pass  the  same  quantity  of  gas. 

And,  conversely,  if  the  length  be  made  l-32nd  of  the  distance, 
the  diameter  may  be  halved. 

Specific  Gravity— Length. 

(16)  If  the  specific  gravity  be  doubled,  the  length  must  be  halved, 

and  vice  versa,  to  satisfy  the  equation. 

Specific  Gravity — Diameter. 

(17)  The  specific  gravity  follows  the  same  laws  as  the  length  does 

in  relation  to  the  diameter. 

It  must  be  borne  in  mind,  when  using  the  above  rules,  that  all  other 
conditions  remain  the  same  when  considering  the  effect  of  one  factor 
on  another  in  the  different  pairs. 

(From  the  "Journal  of  Gas  Lighting.") 


296 


GAS  ENGINEER'S  POCKET-BOOK. 


Service  Pipes. 
If  the  distance  from  the  main  does  not  exceed  30  yards — 

1  to    10  lights  require  f  inch  wrought  iron  tube. 

11  „  30   „     „   1   „     „    „   „ 

31  „  60   „     „  1£  „     „    „   „ 

61  „  120   „     „   li  „     „    „   „ 

120  „  200   „     „  2   „     „    „   „ 

Allowing  for  partial  closing  of  the  pipes  through  corrosion  ;  |  inch  and 
smaller  wrought  iron  tube  should  not  be  used. 

Lead,  copper,  compo.  and  brass  tubes  are  measured  by  outside 
diameter  ;  iron  pipes  are  measured  by  internal  diameter. 

Cast  iron  pipes  should  be  laid  with  a  fall  of  J  inch  per  pipe  for 
outdoor  mains,  with  ground  well  packed  under  joints  before  filling  in, 
and  not  less  than  21  inches  from  surface  of  ground. 


Service  Pipes.     (Shaw.) 


Greatest  Number  of 

Internal  Diameter 

Burners  allowed, 

of  Pipe. 

at  5  Cubic  Feet 

per  Hour. 

Inches. 

| 

10 
25 
45 

Length  of  pipe,   say, 
more  than  100  feet. 

not 

« 

4 

2 

70 
100 
185 

Length   of    pipe,  say, 
more  than  200  feet. 

not 

Services  should  be  connected  to  gas  mains  by  bend  and  hole  in 
top  of  main. 

Half  inch  diameter  services  should  only  be  used  for  public  lamps. 

All  services  in  doubtful  soil  should  be  thoroughly  protected. 

Use  hot  pitch  or  a  mixture  of  sand  and  tar  in  wooden  troughs  to 
prevent  corrosion  of  service  pipes. 


WROUGHT-IRON   TUBES.  297 

Average  Weight  of  Butt-welded  Gas  Tubes  and  Fittings. 


Tubes  Oength  =  14ft.) 

Fittings. 

Bore. 

Weight  per 
100  Feet 
Run. 

Length  re- 
quired to 
weigh  1 
Ton. 

Weight  of  10 
Elbows. 

Weight  of  10 
Tees. 

Weight  of  10 
Crosses. 

Inches. 

Lbs. 

Feet. 

Lbs. 

Ozs. 

Lbs. 

Ozs. 

Lbs. 

Ozs. 

i 

26-3 

8,502 

1 

1 

1 

0 

1 

8 

40-5 

5,532 

1 

7 

1 

8 

1 

14 

| 

57-5 

3.892 

1 

13 

2 

4 

2 

3 

I 

82-9 

2,700 

2 

15 

3 

0 

3 

4 

122-0 

1,836 

4 

6 

5 

4 

5 

11 

i4 

174-9 

1,281 

6 

4 

7 

10 

9 

2 

if 

244-3 

917 

10 

10 

12 

15 

14 

11 

if 

310-2 

722 

15 

8 

16 

7 

18 

10 

i* 

359-5 

623 

15 

12 

20 

0 

21 

4 

2 

421-0 

532 

22 

6 

27 

0 

31 

4 

2* 

515-0 

435 

30 

2 

32 

8 

41 

4 

2£ 

610-4 

367 

46 

2 

50 

15 

51 

4 

2| 

658-8 

340 

55 

10 

68 

8 

80 

10 

3 

759-3 

295 

73 

8 

85 

5 

88 

12 

3£ 

878-4 

255 

101 

0 

121 

0 

129 

0 

4 

1,032-3 

217 

126 

0 

144 

0 

158 

0 

Gas  tubes  are  usually  tested  to  50  Ibs.  per  square  inch.    Water  tubes 
to  300  Ibs.,  and  steam  tubes  to  500  Ibs. 

Weight  of  1,000  Feet  of  Gas  Tube,  Ordinary  Quality. 


iinch    = 


Cwts.    Qrs.      Lbs. 


i 

M 


2 
3 

5 
7 
10 
16 
22 

2 
2 
1 
3 
2 
0 
2 

0 
18 
18 
2 
0 
0 
0 

H  iQ( 
If 
2 

2-! 
2f 
3 

Cwts.    Qrs.      Lbs. 


26 
35 
40 
47 
59 
74 
82 


0 
0 
4 
0 
16 
26 
26 


Table  Showing  Weight  per  Foot  of  Wrought  Iron  Tubing. 


Internal 
Diameter. 

GAS. 

WATER. 

STEAM. 

Weight  per  Foot. 

Weight  per  Foot. 

Weight  per  Foot. 

Inches. 

1* 
H 

ii 

2 

2i 

Lbs. 
0 
1 
1 
2 
3 
4 
5 

Ozs. 
14* 

H 

15 
10 
2* 

«i 

101 

Lbs. 
0 
1 
2 
2 
3 
4 
6 

Ozs. 
15 
7* 

14 
9 
14 
4 

Lbs. 
0 
1 
2 
3 
4 
5 
7 

Ozs. 
15* 
8 
Si 

0 

8 
0 

298 


GAS  ENGINEER'S  POCKET-BOOK. 


Whitworth  Threads  for  Gas  and  Water  Pipes. 


Internal 
Diameter 
of  Pipe. 

External 
Diameter 
of  Pipe. 

Diameter 
at  Bottom 
ot  Thread. 

No.  of 
Threads 
per  Inch. 

Internal 
Diameter 
of  Pipe. 

External 
Diameter 
ot  Pipe. 

Diameter 
at  Bottom 
of  Thread. 

No.  of 
Threads 
per  Inch. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

Inches. 

i 

•3825 

•3367 

28 

li 

2-245 

2-1285 

11 

i 

•518 

•4506 

19 

2 

2-347 

2-2305 

11 

1 

•6563 

•589 

19 

2| 

2-467 

2-351 

11 

* 

•8257 

•7342 

14 

2* 

2-5875 

2-471 

11 

•9022 

•8107 

14 

2| 

2-794 

2-678 

11 

f 

1-041 

•9495 

14 

2* 

3-0013 

2-882 

11 

1 

•189 

1-0975 

14 

2§ 

3-124 

3-009 

11 

1 

•309 

1-1925 

11 

2| 

3-247 

3-1305 

11 

!i 

•492 

1-3755 

11 

*| 

3-367 

3-251 

11 

H 

•65 

1  -5335 

11 

3 

3-485 

3-3685 

11 

if 

•745 

1-6285 

11 

3| 

3-6985 

3-5815 

11 

y 

•8825 

1-705 

11 

H 

3-912 

3-7955 

11 

H 

2-022 

1-965 

11 

3! 

4-1255 

4-0085 

11 

if 

2-16 

2-042 

11 

4 

4-340 

4-223 

11 

Chart  for  Public  Lighting.     (Horstman.) 

Showing  Lighting  and  Extinguishing  Times  for  3,650  hours'  light 
per  annum. 


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JAN.           f£B.      \MA«    /     APR.           MAY          JUNE 
650M     T   Ml    114   II  ittl  «   li   l|>yi    fifKttC  r)IOt7*   IQI7M 
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J                                                                                          s 

COMPARATIVE    PRESSURES. 


299 


Comparison  of  Pressures  in  Inches  of  Mercury,  Feet  of  "Water, 
and  Pounds  per  Square  Inch. 


234567       8       9     10     IT 
Pounds  per  Square  Inch. 


12       13       14        IS 


300 


GAS  ENGINEER'S  POCKET-BOOK. 


30  Ibs.  pressure  per  square  inch  equals  about  a  head  of  70  feet, 
with  a  velocity  of  66  feet  per  second.  Therefore,  area  of  pipe  x  feet 
per  second  equals  discharge  per  second. 

Double  pressure  equals  1£  times  delivery. 

Four  times  length  of  main  equals  £  delivery. 

Double  the  pressure  on  the  district  increases  the  leakage  about 
50  per  cent. 

Other  authorities  say  loss  by  leakage  is  in  direct  proportion  to  the 
pressure. 

Mr.  Hill  found  at  Wallasey  a  loss  of  1-7  per  cent,  between  the 
station  meter  and  the  gasholder  outlet  due  to  temperature,  and  as 
the  "  Sales  of  Gas  Act "  allows  2  per  cent,  fast,  and  3  per  cent,  slow, 
in  the  meters,  he  suggests  that  £  per  cent,  should  be  allowed  off 
leakage  on  this  account. 

With  regard  to  district  pressures  it  may  be  laid  down  as  a  safe  rule 
that  the  lower  the  pressure  can  be  kept,  consistent  with  an  efficient 
and  proper  supply,  the  lower  will  be  the  unaccounted-for  gas. 

Gas  at  the  depth  to  which  the  mains  are  laid,  say  2  feet  as  the 
average,  the  temperature  would  be  between  1°  and  2°  higher  than 
that  of  the  air.  According  to  the  Meteorological  Office  the  mean 
air  temperature  for  the  United  Kingdom  may  be  taken  as  48'69°  F., 
so  that  50°  F.  may  be  taken  to  be  the  average  temperature  of  the 
street-mains  at  a  depth  of  two  feet. 

The  mean  rise  of  temperature  between  the  main  and  the  meter  is 
6£°  ;  some  meters  show  more  and  some  less.  (Lewis  T.  Wright.) 


Transmission  of  Gas  of  0-55  Specific  Gravity  through  Pipes  and 
Bends  (90°).      (Nelson  W:  Perry.) 


Inches 
Pres- 
sure. 

Cubic  Feet. 
Delivered. 

Velocity  of 
Flow  in  Feet 
per  Second. 

Increase 
of  Pressure 
per  Bend. 

Total 
Increased 
Pressure  for 
25  Bends. 

Total 
Initial 
Pressure. 

1 

12,500 

4-0 

0-001  6  in. 

O'Oi       ill. 

1-04 

2 

18.000 

6-0 

0  0034  , 

0-085 

2-085 

3 

23,000 

8-0 

0-00<>     , 

0-1495 

3-15 

4 

25,500 

8-8 

0-007I)  , 

u-189 

4-189 

5 

28,000 

9-6 

0-0081)  . 

0-215 

5-215 

6 

32,000 

11-0 

0-0113  . 

0-28 

6-28 

7 

34,000 

12-0 

0-0135  . 

U-34 

7-34 

8 

36,000 

12-5 

0-0147  , 

0-39 

8-39 

9 

38,500 

13-0 

0-0158  , 

0-4 

9-4 

10 

40,000 

14-0 

0-0183  , 

0-46 

10-46 

Maximum  pressure  should  not  exceed  twenty-tenths  on  district 
where  possible. 

1£  to  2  inches  pressure  at  works  may  be  sufficient  if  the  distributing 
mains  are  of  sufficient  capacity,  and  the  district  fairly  level. 


NAPTHALENE.  301 

Gas,  after  travelling  ten  miles,  has  been  found  to  lose  only  about 

the  coal  by  railroad,  and  generate 


hp  e  coa  , 

electricity  on  the  spot,  than  to  generate  it  and  transmit  the  current 

t  WiO^ordlnary  town  gas  of  16  candle  power,  3,000  H.P.  can  be  sent 
one  mile  for  an  expenditure  of  1  H.P.  =  &  per  cent,  of  the  power 
conveyed. 

Mr.  Wright  estimates  the  true  loss  as  about  65  per  cent,  ot  the 
unaccounted-for  gas  ;  later,  by  another  method,  at  75  per  cent. ;  and 
now,  from  such  examinations  of  the  results  of  the  inferential  as  he 
has  been  able  to  make  (from  the  observation  of  the  amount  of  water 
absorbed  by  the  gas  passing  through  consumers'  wet  meters),  it 
appears  to  him  safe  to  say  that  the  bulk  of  the  unaccounted-for  gas  is 
actual  loss  from  the  distributing  system,  always,  of  course,  assuming 
the  meter  registration  to  be  reasonably  correct. 

Napthalene  arises  from  the  H  of  the  gas  passing  through  the 
main,  by  the  action  of  the  exosmose,  and  thus  the  carbon,  deprived 
of  its  diluent,  is  deposited  in  its  solid  state.  (Dr.  Frankland.) 

If  this  were  the  case  napthalene  would  always  be  deposited, 
which  is  not  the  case. 

Napthalene  is  found  wherever  there  is  a  condensation  of  the 
aqueous  vapour  contained  in  the  gas.  If  the  aqueous  vapour  is 
removed  from  the  gas,  napthalene  is  not  deposited  under  ordinary 
conditions  of  temperature  and  pressure.  (Bremond.) 

Napthalene  is  generally  only  found  when  mains  or  services  are 
laid  less  than  1  foot  from  the  surface  of  the  ground. 

Every  deposit  of  napthalene  equals  a  reduction  of  illuminating 
power  in  the  gas. 

Naptha  dissolves  napthalene. 

No  napthalene  found  in  mains  since  water  gas  used  at  Blackburn. 

Napthalene  is  not  likely  to  be  found  in  mains  if  the  gas  contains 
more  than  2  per  cent,  benzol.  (Col.  Sadler.) 

Of  all  enrichers,  benzene,  for  the  average  consumer  of  gas,  gives 
the  greatest  value  for  the  money. 

Toluene  and  xylcne  are  better  enrichers  ;  but  their  non-volatility 
precludes  their  employment. 

One  gallon  of  benzol  enriches  9,500  feet  1  candle,  and  1  gallon 
of  carburine  will  improve  2,800  cubic  feet  to  the  same  extent 
(Mr.  Hunt.) 

The  temperature  at  which  benzol  volatilizes  is  a  convenient  one, 
as  ordinary  steam  heat  is  all  that  is  required. 

The  amount  of  benzol  vapour  which  common  coal  gas  can  per- 
manently retain,  viz.,  over  50  grains  per  cubic  foot  at  0°  C.,  is  greater 
by  far  than  anything  required  to  enrich  low-quality  gas  to  any 
reasonable  extent. 

Benzol  at  a  temperature  of  70°  to  80°  C.  will  dissolve  2£  to  2|  Ibs. 
of  sulphur  per  gallon,  but  when  cooled  to  25°  C.  it  will  only  retain 
£  Ib.  per  gallon. 

Between  7  and  9  grains  of  benzol  vapour  will  improve  1  cubic 
foot  of  gas  between  4  and  5  candles.  (Dr.  Bunte.) 


302  GAS  ENGINEER'S  POCKET-BOOKO 

The  results  of  disillumined  gas  plus  benzene  are — 

0-0221  gramme  per  litre  gives  1-3  candles 
0-0385  ,  4-1 


0-0544 
0-0630 
0-0863 
0-0881 
0-1231 


7-6  „ 

9-6  „ 

21-0  „ 

20-2  „ 

30-0  „  (Irwin.) 


Benzene  gives  about  -4  candles  per  gallon  per  1,000  cubic  feet. 

Gas  enriched  1  Candle  by 
1  Gallon  of  the  Liquid. 
Benzol  (chemically  pure)         ....     13,300  cubic  feet. 

Benzol  (90°) 12,500     „        „ 

Carburine  (680  specific  gravity)      .         .        .       5,700     „         „ 
Common  petroleum  spirit  (700  specific  gravity)       4,300     „         „ 

In  an  enricher  a  carbon  atom  combined  with  H4  or  H3  is  useless  ; 
a  carbon  atom  combined  with  H2  possesses  enriching  power  ;  a  carbon 
atom  combined  with  Hx  possesses  two  or  three  times  the  enriching 
power  of  the  foregoing  ;  and  a  carbon  atom  combined  only  with  other 
carbon  atoms  again  possesses  two  or  three  times  the  enriching  power 
of  a  carbon  atom  combined  with  H.  (W.  Irwin.) 

By  admitting  alcohol  vapour,  in  regulated  amount,  to  the  gas  main, 
the  illuminating  power  of  the  gas  is  unaffected  thereby,  though  the 
freezing-up  of  the  services  is  prevented.  The  alcohol  is  vaporized  by 
steam  or  direct  heating  just  before  admission  to  the  main,  and  the 
quantity  is  regulated  according  to  the  amount  of  gas  passing  per 
hour  and  the  prevailing  degree  of  cold.  (Dr.  J.  Buel.) 


Disillumined  Gas  and  Heptane  (prepared  by  Fractionating  Petroleum 

Spirit). 

0-0528  gramme  per  litre  gives  2-15  candles. 
0-1010        „         '     „  „     6-35       „ 

0-1516       „  „  „    11-10      „ 

Napthalene  is  the  cheapest  and  greatest  enricher,  but  it  cannot  be 
supplied  with  gas  from  the  gas-works  because  of  its  non-volatility. 
It  could,  however,  be  used  for  the  street  lamps  with  a  carburetting 
apparatus,  which  would  give  50  per  cent,  more  light  for  a  mere 
fraction.  Were  separate  mains  employed  and  water  gas  used  in  con- 
nection with  napthalene,  the  cost  of  street  lighting  would  be  reduced 
to  a  minimum.  (W.  Irwin.) 

In  napthalene  not  more  than  44  per  cent,  of  the  weight  added  to 
the  gas  is  really  utilized  in  emitting  light. 

The  napthalene  in  the  gas  in  street  mains  may  be  held  in  suspen- 
sion, by  admitting  gasolene  into  the  main  outlet  pipe  leading  from 
the  works  to  the  street  main  system,  by  reason  of  its  greater  affinity 
for  it  than  moisture  has. 

Napthalene  melts  at  174°  F.  and  boils  at  428°  F, 


NUMBKli   OF    FEET    FOR   ONE    PENNY. 


303 


8-S5-    8    8   §    g  j; 

!**•§*•§« 

I  «•     »    *  =3  -°  J 


^    Illll 

8    4»*S- 
8    «•§  8P-S 


HUMBEIt    Of    CUBIC    FftT    fOH    ONt    PtNMY 


304 


GAS  ENGINEER'S  POCKET  BOOK. 


Comparison  of  Prices  of  Gas  in  Sterling  and  French  Monies. 

Price  per  1,000  Cubic  Feet. 
i2/-     i3/-    i4/-     i5/-     i6/-    i7/-     i8/-     ig/-     20/-    2i/-     22/-     23/- 


90 


2/-       3/~       4/~       S/~       61-      7 1-      8/-      g/-      io/-     xi/- 
Price  per  1,000  Cubic  Feet  in  Shillings  and  Pence. 


RELATIVE    VALUES    OF    ILLUMINATING   AGENTS. 


305 


Oxygen  required  for  Complete  Combustion. 

volume  Methane  requires  .        .     .  2'0  volumes  Oxygen. 

Hydrogen      „  .         .  0'5        „ 

Benzol            „  .         .     .  7'5 

Propylene      „  .        .  4-5 

Ethylene  .     .  3-0 


Carbon  monoxide 


0-5 


(M.  Casaubon.) 


Relative  Values  of  Illuminating  Agents.     (Dr.  Letheby.) 

In  respect  to  their  vitiating  and  heating  effects  on  the  atmosphere, 
when  burning  so  as  to  give  the  light  of  12  standard  sperm  candles. 


Thermal 
Units  of 
Heat. 

Oxygen 
Consumed. 

Carbonic 
Acid 
Produced. 

Air 
Vitiated. 

Cubic  Feet. 

Cubic  Feet. 

Cubic  Feet. 

Cannel  Gas 

1-950 

3-30 

2-01 

50-2 

Common  Gas       .     . 

2-786 

5-45 

3-21 

80-2 

Sperm  Oil 

2-325 

4-75 

3-33 

83-3 

Benzol          .         .     . 

2-326 

4-46 

3-54 

88-5 

Paraffin    . 

3-619 

6-81 

4-50 

112-5 

Camphine     .        .     . 

3-251 

6-65 

4-77 

119-2 

Sperm  Candles 

3-517 

7-57 

5-27 

131-7 

Wax        „             .     . 

3-831 

8-41 

5-90 

149-5 

Stearic    „ 

3-747 

8-82 

6-25 

156-2 

Tallow    „             .     . 

5-034 

12-06 

8-73 

218-3 

Gas   Consumed  and  Carbon  Dioxide   Produced  per  hour  to   Yield 
an  Illumination  of  48  Candles.     (16-5  Candle  Gas.) 

(Professor  Lewes,  June,  1893.) 


Illumination 
Value  per 
Cubic  Foot. 

Gas 
Consumed. 

C02 
Produced. 

No.  of 
Adults  to 
Produce  CO2 

Flat  flame  No.  6      . 

2-5 

19-2 

10-1 

16-8 

»        >»       1.    5 

2-1 

22-9 

12-1 

20-1 

»        i>       »    * 

1-9 

25-3 

13-4 

22-3 

London  Argand 

3-3 

15-0 

7-9 

13-1 

Regenerative   . 

u-o 

4-8 

2-5 

4-1 

Paraffin  Lamps 

— 

— 

13-5 

22-5 

Candles,  sperm 

— 

— 

19  '(52 

32-7 

G.E. 


306  GAS  ENGINEER'S  POCKET-BOOK. 

Duty  in  Candles  of  Various  Burners  at  5  feet  per  Hour. 

(J.  H.  Cox,  Junior.) 

Duty  in 
Candles. 

Standard  Argand 16 

Public  lamps,  average 13.] 

Good  batswing  after  1  year's  use,  rather  dirty        „     10 
Good  batswing  after  being  cleaned         .         .         .     13^ 
Iron  batswing.  corroded  and  old          .         .         ,     .       7^ 
Iron  fishtail,  corroded  and  old         .        .         .         •       *H 
Iron  batswing,  corroded  and  old          .         .         ,     .       6 
Iron  batswing,  corroded  and  old  3| 

Wasteful  Argand .       5£ 

Peebles'  5  feet  regulator  burner      .        .        .         ,14^ 
Bray's  No.  8  flat  flame  burner    .        .        .         .     „     14 
Borrowdail's  governor  burner.        .        .        .         c     13| 

Sugg's  Christiania  burner 14 

A  good   unregulated    burner  under  unnecessary 

pressure 8 

Same  burner  regulated 12£ 

Number  1  Argand,  at  5  cubic  feet  per  hour  .  .16 
Number  1  Argand  turned  down  to  3  cubic  feet .  .  8 
Wenham  lamp  ground  glass  shade,  at  45°  .  .  22 

Average  of  above  18  burners       .        .    .     11£ 


Other  Illuminants  under  Best  Conditions.     (J.  H.  Cox,  Junior.) 
In  candles  per  Id, 

Electricity  (incandescent),  at  %d.  per  hour  per 

8  candle  lamp 3J 

Candles — Palmatine  candles  6  to  1  lb.,  at  10d. 
per  pound,  9  inches  long  burning  1  inch  per 
hour.  Illuminating  power  corrected  to 
120  grains  per  hour,  1£  standard  candles  .  § 

Oil — Petroleum  burnt  under  best  conditions  in 
a  20  candle  duplex  lamp  (oil  at  1*.  per 
gallon) 9i 

Burners  when  lighted  uso  less  gas  than  when  fumed  on  and  not 
lighted  ;  a  No.  3  burner  lighted  consumes  3  cubic  feet,  unlightcd 
3i  cubic  feet  per  hour. 

•  Effects  of  different  pressures  on  a  No.  4  union  jet  burner  : — 
Pressure  in  inches .         .     0'5       1-0       1-5       2-0       2*5       3'0 
Consumption,  cubic  feet     3'9       5-6       7-0       8'45     9'6     10  5 
Unit  efficiency,  candles .     3-0      2-4       1-9       15       1-35     I'll 


VITIATION    OP    AIR. 


307 


Carbon  and  Hydrogen  Escaping  Unconsumed  per  100  parts  C., 
Completely  Burned.     (W.  Thomson,  1890.) 


Carbon. 

Hydrogen. 

Petroleum  lamp,  not  burning  at  the  full  . 
„             „     with  flame  turned  full  on 

1-204 

0-309 

Argand  gas  flame       

— 

0-025 

0-011 

0-254 

Bray  burner,  consuming  4  cubic  feet  pur 

hour    

1-112 

0-095 

Welsbach  burner  

1-5 

0-379 

Marsh-Greenall's  heating-stove  burning  • 

5-62  cubic  feet  per  hour 

1-26 

0-3 

5-74      „        „         „             .... 

3-76 

1-18 

7-10      „„„.... 

9-74 

1-21 

Thos.  Fletcher's  heating  stove  :  — 

with  8  Bunsen  burners       .        .         .     . 

4-33 

2-46 

burning  6-81  cubic  feet  per  hour   . 

6-63 

2-0 

with  20  Bunsen  burners  with  asbestos 

and  fire-clay   back  consuming  8'14 

cubic  feet  per  hour         .        .         .     . 

13-89 

1-17 

Heating  stove         

20-0 

— 

Vitiates 
per  Hour. 

Units  of  Heat 
Generated. 

Cubic  Feet. 

An  adult  man      .... 

215 

190 

Each  cubic  foot  of  gas  burned   . 

8'5 

600 

Each  pound  of  oil  burned  . 
„          „           candles  burned    . 

150 
160 

|  16,000 

Daylight  on  a  well  exposed  table  equals  4'6  foot  candles. 

Minimum  required  for  reading  without  fatigue  equals  1  candle  at 
1  foot. 

Minimum  required  for  fluent  reading  equals  1*4  to  2-3  candles  at 
1  foot. 

Minimum  required  for  street  lighting  equals  0'09  candles  at  1  foot. 

(Cohn  and  Wybauw.) 

The  light  from  the  edge  of  a  petroleum  lamp  flame  equals  62  to  63 
per  cent,  of  that  from  the  flat  side. 

The  reflective  power  of  a  whitewashed  ceiling  equals  a  loss  of  light 
of  only  20  per  cent,     (H.  E.  Harrison.) 

The  intensity  of  illumination  on  a  given  surface  is  inversely  as  the 
square  of  the  distance  from  the  source  of  light. 


X  2 


GAS  ENGINEER'S  POCKET-BOOK. 

Adults  inhale  about  1  pint  of  air  at  each  breath  and  take  18  to  20 
breaths  a  minute. 

The  heat  evolved  by  a  gas  flame  is  the  best  of  all  ventilating 
mediums,  provided  a  simple  means  is  secured  for  conveying  the 
products  of  combustion  out  of  the  room. 

It  is  said  that  the  injury  done  to  books  by  gaslights  is  not  due  to 
the  sulphur  in  the  £,as  but  by  what  is  called  carbon  oxysulphide, 
condensing  on  any  object  a  foot  or  so  below  the  ceiling. 

If  a  chimney  is  properly  constructed  it  may  be  used  for  a  venti- 
lating flue,  and  be  able  to  give  a  pull  of  one  and  half  to  two  tenths 
of  an  inch  vacuum,  which  is  sufficient  to  convey  away  all  the  vitiated 
air  from  a  room  if  the  flue  pipes  are  large  enough. 

Temperature  cf  air  in  rooms  should  not  be  more  than  10°  higher  at 
1  foot  from  the  ceiling  than  at  1  foot  from  the  floor. 

Two- tenths  of  an  inch  draught  gives  a  velocity  of  air  of  about 
6  feet  per  second. 

Inflowing  air  should,  if  possible,  be  warmed  to  within  10°  or  15°  of 
the  temperature  of  the  room. 

The  rarer  the  atmosphere  the  larger  the  flame ;  the  denser  the 
atmosphere  the  smaller  the  flame. 

When  coal  gas  is  burnt  sulphur  is  liberated  as  sulphur  dioxide,  but 
this  is  not  further  oxidized  to  sulphuric  acid  (H2S04)  unless  the  tem- 
perature falls  so  greatly  that  water  is  deposited. " 

A  certain  amount  of  sulphurous  acid  is  no  doubt  formed  wherever 
gas  is  burnt,  and  this  may,  in  the  presence  of  moisture,  be  converted 
into  sulphuric  acid,  but  when  ordinary  ventilation  is  used,  the  amount 
must  be  very  trifling. 

Dust  collected  in  rooms  where  no  gas  is  burnt  is  found  to  contain 
an  equal  quantity  of  sulphates  as  that  found  in  gas-lighted  rooms. 

No  instance  of  imperfect  combustion  has  been  ever  substantiated 
against  lighting-burners,  nor  even  against  heating-burners  of  good 
class  when  employed  under  their  normal  working  conditions. 
(L.  T.  Wright.) 

C02  in  gas  has  more  effect  on  a  flat  flame  than  in  an  Argand  in 
reducing  the  light,  the  depreciation  being  less  the  higher  the  candle 
power. 

No  trace  of  CO  or  acetylene  was  found  in  the  products  of  combus- 
tion from  Welsbach,  Argand,  and  Bray  burners.  (Lancet.} 

Two  cubic  feet  H  +  1  cubic  foot  O  forms  2  cubic  feet  aqueous 
vapour. 

By  heating  the  air  and  gas  before  combustion,  the  carbon  particles 
in  the  gas  are  liberated  earlier  and  brought  to  a  higher  temperature, 
at  the  same  time  they  are  kept  at  this  temperature  for  a  longer 
period. 

The  burner  tip  should  be  of  a  non-conducting  nature,  as  steatite,  so 
as  not  to  reduce  the  intensity  of  combustion. 

In  Argand  burners  the  supply  pipes  to  the  ring  are  generally  of 
smaller  area  than  the  sum  of  the  areas  of  the  holes  in  the  latter  so  as 
to  reduce  the  pressure  at  the  point  of  consumption. 

Angle  at  which  the  mean  intensity  of  flat  flame  burners  is  obtained 
varies  from  1-5°  *o  10'25°,  average  4-68°.  (A.  C.  Humphreys.) 


PROPER    HEIGHT   OP    LAMPS. 


309 


Sizes  of  Internal  Pipes,  Lead  and  Iron,  According  to  Number  of 
Burners  Required,  as  Allowed  by  Blackpool  Corporation  Gas 
Department. 


Internal 
Diameter 
of  Pipe. 

Greatest 
Length 
Allowed. 

Greatest  No. 
of  Burners. 

Internal 
Diameter 
of  Pipe. 

Greatest 
Length 
Allowed. 

Greatest  No. 
of  Burners. 

Inches. 
| 

I 

Feet. 
20 
30 
40 
50 

3 
6 
12 
20 

Inches. 

1 

H 
H 

2 

Feet. 
80 
100 
150 
200 

40 
60 
100 
200 

Light  absorbed  by  clear  glass  globes 
„  „         „      „    engraved  globes  . 

,,  „         „    globe  of  ordinary  pattern 

„  „         „        „    obscured  all  over 

„  „         „     white  opal  globe 

„  „          „     painted  opal  globe 


12  percent. 
24    „       „ 
35    „       „ 

40  „  „ 
60  „  „ 
64  , 


Clear  glass  prevents  10*57  of  the  light  from  passing  through  it, 
ground  glass  stops  29'48,  smooth  opal  glass  over  52'83,  and  ground 
opal  more,  55'85. 

Formula  for  determining  the  height  of  lamps  for  a  known  radius 
of  lighting — 

h  =  I  J  2~=  0-7  I 

The  proper  height  of  any  light  should  be  0-7  of  the  area  to  be 
lighted  by  any  one  light.  (Electrical  Committee  Chicago  Exhibition.) 

The  proper  height  of  any  light  should  be  such  as  to  give  an  angle 
of  7°  to  the  most  distant  point  it  is  intended  to  serve.  (Professor 
H.  Robinson.) 

For  comparisons  of  lighting  he  reduces  the  various  distances,  etc., 
to  a  co-efficient. 

Candle  power  of  lamp  X  height  of  lamp  in  feet 
distance  from  lamp  to  farthest  point  served  in  feet  3 

With  Argand  or  flat  flame  burners  free  to  the  air,  the  distribution  of 
light  upon  a  circumscribing  sphere  of  radius  1  is  equal,  but  this  is  not 
the  case  with  regenerative  or  incandescent  burners.  (W.  Hy.  Webber.) 


Table  of  Lighting.     (Deduced  from  R.  Richards.) 


Street  lighting 
Church     ',', 

Theatre     " 

Public  halls  lighting 

Workshop          „       . 


Road  or  pavement   . 

Walls  . 

General   . 

Pew  or  reading  desk 

Auditorium 

General  area 


candle  foot. 


2  to 


310  GAS  ENGINEER'S  POCKET-BOOK. 

Table  of  Lighting,     (Deduced  from  R.  Richards)— continued. 

Workshop  lighting       Benches 3^  candle  foot. 

„  „       .     Optical  or  fine  work         .         .5          „        „ 

Domestic  „  Corridors,  passages,  halls,  etc.       f        „        „ 

„  „       .     Living  rooms        .        .        .    .     |        .,         „ 

„  „  Library,  study,  or  bedroom      .     \        „         ., 

„  „       .    Table  lighting         ...  2          „         „ 

The  sun's  light  equals  about  5,600  candles  placed  at  a  distance  of 
30  centimetres. 

The  moon's  light  equals  about  ^th  candle  placed  at  a  distance  of 
3 '65  metres. 

The  sun's  light  equals  5,500  candles  placed  at  a  distance  of  12  inches 
(another  authority). 

Formula  to  Find  the  Intensity  of  Light  any  Distance. 

Initial  power  of  the  light 
Intensity  =-         Fdi6tancea 

Formula  to  find  the  Initial  Intensity  of  any  Light. 

Initial  intensity  =  intensity  found  at  any  point  X  distance  of  that 
point  from  the  source  of  light 2. 

Formula  to  find  distance  at  which  any  Intensity  will  be  found. 


/Initial  power  of  the  light 
Distance  =  V  -       Intensity  desired 

Formula   to  find   Intensity  of   Light  falling  upon  a  point  in  a 
horizontal  plane  from  a  source  above  it. 

Illuminating  power  of  source  X  vertical  height  above  plane 
Slant  distance3 

German  Experiments  show  that  a  light  of  1  candle  power  can  be 
seen  1-4  mile  on  a  clear  dark  night,  and  1*0  mile  on  a  rainy  night. 

American  Experiments  show  that  in  clear  weather  a  light  of 

1  candle  power  is  visible  at  .         .        .1  mile. 

3       „  „  „         (with  a  binocular)        2  miles. 

10  „  ,,  ,,  „  »  }> 

20      „  „  „         (faintly)      .         .     .     5     „ 

33       „  „  „        (easily)   .        .         .     5     „ 

Dutch  Experiments  show  that  a  light  of 

1  candle  power  is  visible  at  1  mile 
3}     „          ,,          „       „        2  miles 
16  ;,        .,        5     „ 


VENTILATION. 


311 


A  green  light  to  be  seen  at 

1  mile  at  sea  must  be  of  2  candle  power. 

2  miles    „          „        „     15       „  „ 

**      »          n  »          »       "•*•        i?  *> 

4     n         »  »          ,.     106       „  ,, 

The  shade  of  green  recommended  is  a  clear  blue  green  ;  the  shade 
of  red  a  coppery  red.  Ked  lights  show  better  than  green  ones  at  the 
same  distance. 

One  light  of  whatever  intensity  is  not  perceptible  to  our  eyes  in 
presence  of  a  light  64  times  brighter.  (Bouguer.) 

The  intensity  of  illumination  which  is  received  obliquely  is  pro- 
portional to  the  cosine  of  the  angle  which  the  luminous  rays  make 
with  the  normal  to  the  illuminated  surface.     (Dr.  Atkinson.) 
Freshly  fallen  snow  reflects  78  per  cent,  of  light. 
White  paper  „       70 

„      sandstone  „        24        „  „ 

Ordinary  earth,  road 
surfaces,  etc. 


8 


Old  Rule  for  Numbers  of  Burners  Required  for  Effective  Lighting- 
Floor  area  in  square  feet 
50 

Ventilation  Notes. 

Ventilation  should  be  arranged  so  as  to  change  the  air  in  a  room 
in  10  minutes  as  a  maximum. 

With  a  6-inch  vertical  flue  12  feet  long  the  most  economical  burner 
to  use  is  one  of  1  cubic  foot  per  hour  capacity,  this  will  remove 
2,460  cubic  feet  of  air  per  hour. 

The  maximum  consumption  of  gas  in  a  ventilating  flue  should  not 
exceed  5  cubic  feet  per  hour  for  each  circular  foot  area  of  section. 

The  atmospheric  and  illuminating  flame  is  the  same  in  all  cases 
where  a  large  quantity  of  air  has  to  be  heated  to  a  low  temperature. 
The  consumption  of  1  cubic  foot  of  gas  in  a  ventilating  shaft  can  be 
made  to  remove  more  than  2,400  times  its  own  bulk. 

Normal  air  contains  0'364  grains  C02  per  foot. 

Air  to  be  pure  should  not  contain  more  than  7  grains  C02  per 
cubic  foot. 

Adult  expires  15  cubic  feet  of  air  per  hour,  containing  4J  per  cent. 
C02  =  '8  cubic  feet  per  hour. 

Air  at  60°  should  not  contain  more  than  5  grains  moisture. 


l  Adult. 

1  Cubic 
Foot  Gas. 

Cubic  feet  of  C02  per  hour  given  off  by    . 

0-8 

0-5 

Heat  units  given  off  by          .         .        .     . 

480 

620 

Grains  per  cubic  foot  of  water  vapour 
Cubic  feet  of  air  actually  used  by         .     . 

200 
15 

440 
60 

,,        „         „      vitiated  in  an  unventi- 

latcd  room  . 

1,200 

800 

312  GAS  ENGINEER'S  POCKET-BOOK. 

Ventilation  should  be  2,000  to  3,000  cubic  feet  per  hour. 

About  3  cubic  feet  to  4  cubic  feet  per  minute  of  air  is  required  for 
each  adult.  Sleeping  apartments  should  have  about  1,000  cubic  feet 
per  occupant.  Workshops  and  living  rooms  not  less  than  600  cubic 
feet  per  person. 

For  each  lamp  or  gas  burner  from  30  to  60  cubic  feet  of  air  is 
required  per  hour. 

A  4 -inch  shaft  8  feet  long,  with  the  help  of  a  jet  of  gas  burning 
£  to  |  of  a  cubic  foot  per  hour,  will  aspirate  upwards  of  1,100  cubic 
feet  of  air  per  hour  in  a  still  atmosphere,  and  with  further  assistance 
of  a  wind  moving  across  the  ventilator  at  a  velocity  of  4£  feet  per 
second,  it  will  aspirate  3,126  cubic  feet  per  hour. 

A  6-inch  similar  cowl,  with  a  burner  consuming  4  cubic  feet  of  gas 
per  hour,  will,  in  a  still  atmosphere,  aspirate  about  2,500  cubic  feet  of 
air  per  hour,  and  with  the  assistance  of  wind  moving  at  the  velocity 
of  9  feet  per  second  it  will  aspirate  6,840  feet  per  hour.  (W.  Sugg.) 

Professor  Smithells  concludes  that  when  compounds  of  carbon  and 
hydrogen  meet  oxygen  the  C  is  first  oxidised  and  the  H  liberated, 
which  is  then  converted  into  steam  by  oxidation.  The  light  of  the 
flame  being  due  to  carbon  formed  by  the  decomposition  of  hydro- 
carbons by  the  heat  of  the  primary  combustion,  according  to  the 
equation  :— 3  C2H4  =  2  CH4  +  4  CH  +  2  H2. 

Professor  Lewes  believes  that  the  H  rapidly,  and  the  methanes 
slowly,  diffuse  to  the  outside  of  the  flame,  and  are  burned,  producing 
heat  sufficient  to  raise  the  temperature  of  the  gas  to  1,000°  C.,  at 
which  temperature  the  unsaturated  hydrocarbons  and  the  higher 
saturated  carbons  and  hydrogen  compounds  being  decomposed  into 
acetylene,  the  heat  rising  to  1,200°  C.  changes  the  acetylene  into 
C  and  O,  and  the  C  becoming  incandescent  gives  off  the  light. 

Gas-flames  with  an  ample  supply  of  primary  air  when  in  contact 
with  incandescent  surfaces,  do  not  discharge  combustible  gases 
among  the  products  of  combustion. 

Professor  Macadam  found  that  with  4*85  candle  power  per  foot 
gas,  the  best  value  with  a  Welsbach  S  burner  was  10*66  candle  power 
per  foot,  with  7*12  candle  power  per  foot  gas  it  was  12*75  candle 
power  per  foot,  and  with  2*80  candle  power  per  foot  gas  it  was 
13*63  candle  power  per  foot. 

The  loss  by  different  glasses,  etc.,  is  shown  as  follows  : 

Clear  glass  1  cubic  foot   =  12*81  candle  power. 
Mica     ....     =12-81      „  „ 

Amber  glass  1  cubic  foot=  12*18     „  „ 

Kuby  glass  .        .     =  9*06     „  „ 

When  gas  gets  much  above  24  candle  power,  it  is  not  advantageous 
to  employ  the  ordinary  form  of  Welsbach  C  burner  as  supplied  by 
the  company  at  the  time  (1895).  (Professor  W.  I.  Macadam.) 

By  a  more  perfect  admission  of  gas  and  air  in  a  Bunsen  burner,  a 
corresponding  heat  development  ensues,  and  a  light  equal  to  27 
candles  per  cubic  foot  can  be  obtained  with  16  candle  gas  and 
without  a  chimney  with  the  Welsbach- Deuayrouze  burner. 


COMPARATIVE  COST   OF   DIFFERENT   LIGHTS. 


313 


Number  of  Candle-power  Hours  which  can  be  Provided  at 
the  Same  Cost.     (Prof.  D.  E.  Jones.) 


Wax          .... 

Stearine  .  .  .  . 
Incandescent  electric  light 
Coal  gas  (slit  burner)  . 
Acetylene  and  air  (slit 
burner).  .  .  . 
Oil  gas  .... 
Water  gas  and  benzene  . 


33 

77 
440 
625 

716 
1.660 
1^666 

Electric  arc       .         .      •  .   2,322 
Schulke's      petroleum-gas 
lamp          .         ...    2,250 
Auer  -  Welsbach     burner 
with  coal  gas         .         .    2,300 
Auer  -  Welsbach     burner 
with  water  gas          .     .    4,350 

Comparative  Cost  of  Different  Illuminants  (Germany). 

Gas  Argand  burner    .......  943^. 

„     small  Wenham  burner    ......  483*2. 

„    carburetted  with  napthalene,  No.  2  Bray  burner  574<?. 

„     Welsbach  burner         ......  305^. 

Petroleum,  large  centre  draught  burner        .         .     .  449d. 

„          small  burner     ......  589d. 

Electric  glow  lamp  .  .  .  .  .  . 


The  comparative  cost  of  a  duplex  lamp,  with  paraffin  at  Sd.  a 
gallon  equals  5'63d.  per  1,000  candles  per  hour. 

The  comparative  cost  of  a  Lamp  Beige,  with  paraffin  at  Is.  a 
gallon  equals  7*9<f.  per  1,000  candles  per  hour. 

The  comparative  cost  of  Schulke  regenerative  lamp,  with  gas  at 
2s.  3d.  per  1,000  feet  equals  2-9^.  per  1,000  candles  per  hour. 

The  comparative  cost  of  Wenham  regenerative  lamp,  with  gas  at 
2s.  3d.  per  1,000  feet  equals  4'lrf.  per  1,000  candles  per  hour. 

The  comparative  cost  of  ordinary  flat  flame  burner  equals  8'3^.  per 
1,000  candles  per  hour.  (L.  T.  Wright.) 


Incandescent  Electric  Lamps. 


Number  of  Hours 
the  Lamp 
has  been  alight. 

Illuminating 
Power. 

Number  of  Hours 
the  Lamp 
has  been  alight. 

Illuminating 
Power. 

0 

14-8 

453 

10-8 

96 

14-0 

520 

11-5 

168 

13-3 

612 

10-5 

307 

11-5 

709 

10-5 

357 

11-8 

761 

10-5 

314  GAS  ENGINEER'S  POCKET-BOOK. 

Eelative  Cost  of  Illuminants. 

Gas  at  3s.  per  1,000  cubic  feet  (16  caudle)  with  flat  flames  equals  1. 

Composite  candles,  each  burning  136  grains  per  hour  at  1*.  per 
Ib.  equals  16-6. 

Mould  tallow  candles,  each  burning  145  grains  per  hour  at 
6d.  per  Ib.  equals  18'0. 

Wax  candles,  each  burning  165  grains  per  hour  at  Is.  per  Ib.  equals 
22-6. 

Sperm  candles,  each  burning  133  grains  per  hour  at  2*.  per  Ib. 
equals  34*3. 

Some  20  to  60  per  cent,  more  sulphur  is  given  off  from  paraffin 
lamps  than  from  gas  lamps. 

Table  Showing  the  Luminous  Effect  of  a  Square  Centimetre 
of  Flame  Area.     (M.  Mourner.) 

In  a  jet  gas  flame 0*06  candle. 

„  an  Argand  burner        .         .         .     .       0'3        „ 
„  a  Siemen's  burner    .        .        .  0'6        „ 

„  incandescent  electric  lamps        .     .     30'0        ,', 
„  the  electric  arc         ....  480'0       ., 

Gas  Stove  Notes.  (Lrnir <>£,*) 

1.  It  is  desirable  that  the  stove  should  afford  radiant  heat  only. 

2.  For  this  purpose  some  form  of  clay  "  fuel  "  is  best. 

3.  Attention  should  be  given  to  the  packing  of  the  "  fuel  "  so  as  to 
avoid  undue  clogging  or  impeding  the  flow  of  the  flames. 

4.  The  stove  should  be  supplied  with  separate  burners  with  taps. 

5.  Some   means    of    controlling  the   supply  should  be  adopted. 
Governors  or  regulators  are  indicated. 

6.  A  simple  arrangement  appears  to  be  necessary  by  which  undue 
drying  of  the  warmed  air  may  be  avoided. 

7.  Indestructible   enamel,   or  enamel  little  affected  by  the  heat, 
should  be  used  for  coating  the  stove  ;   common  paint,   varnish  or 
ordinary  enamel  should  be  avoided. 

8.  An  efficient  flue  should  in  all  cases  be  provided  with  gas  fires, 
however,  the  flue  pipe  may  be  much  smaller  than  the  chimney 
required  by  coal  fires. 

9.  The  burner  should  be  as  far  as  possible  noiseless. 

Pressure  for  gas  stoves  should  not  be  less  than  four-tenths,  eight- 
tenths  best. 

One  volume  of  gas  requires  5£  volumes  air  for  complete  combustion. 

Average  mixture  of  gas  and  air  in  gas  stove  Bunseu  burners  is! 
1  to  2-3,  remainder  3'2  is  supplied  around  the  flame. 

On  a  large  scale  one  pound  of  meat  can  be  cooked  by  1  cubic  foot. 
of  gas. 

Gases  in  flues  of  gas  stoves  consist  of  about :— Oxygen,  12  pc  J 
cent. ;  Nitrogen,  84  per  cent. ;  CO2  4  per  cent. 

40  cubic  feet  of  gas  in  an  average  gas  stove  raised  the  temperature 
of  a  room  1,080  cubic  feet,  5°  F. 


GAS   STOVES. 


315 


Size  of  Pipes  and  Lengths  Allowed  for  Gas  Stoves  by  Blackpool 
Corporation  Gas  Department. 


Average  Inside  Size  of  Oven. 

Distance  of  Stove 
from  Meter. 

Pipe 
Required. 

11    inches  X  11    inches  X  14  inches 

under  30  feet 

%  inch. 

11        „       Xll        „       X14 

if  60 

A 

14        „       X14        „       X24 

if  30 

I 

14 

X14 

X24 

if  60 

I 

15i 

X  15£ 

X  24 

if  30 

15i 

Xl5i 

X24 

if  60 

1 

19 

X  18 

X24 

if  30 

1 

19 

X18 

X24 

if  60    ., 

H 

Connect  all  gas  stoves  with  a  large  gas  supply  and  with  full-way 
taps  and  fittings.  The  chimney  should  be  closed  with  a  wrought  iron 
plate  with  a  hole  in  it  to  allow  the  flue  of  the  gas  stove  to  pass 
through. 

One  degree  F.  rise  in  temperature  per  15*4  cubic  feet  gas  consumed. 
Seven  Ibs.  coal  required  for  same  rise  in  temperature.  (Professor 
Lewes.) 

Total  calorific  value  of  gas  is  constant,  whether  Bunsen  or 
luminous  flames  are  used,  if  complete  combustion  is  assured.  The 
latter,  however,  must  be  kept  sufficiently  far  from  the  object  being 
heated  so  that  the  flame  may  not  impinge  upon  its  surface,  or  soot 
will  be  deposited,  forming  a  non-heat-conducting  layer,  and  so 
diminish  the  energy  of  the  flame. 

As  regards  the  calorific  value  of  the  gas — 


Carburetted  water  gas  145° 
Coal  gas  .  .  .  136° 
Mixed  gas  .  .  .  136° 


per  4  2  cubic  feet. 


The  permanent  gas  from  the  flue  of  a  gas  stove  consists  wholly  of 
C02,  N  and  0.    (Lancet) 


Warming  by  Steam. 

When  the  external  temperature  is  10°  below  freezing  point,  in  order 
to  maintain  a  temperature  of  60° — 

One  square  foot  steam  pipe  for  each  6  square  feet  glass  in  windows. 

One  square  foot  steam  pipe  for  every  6  cubic  feet  of  air  escaping 
for  ventilation  per  minute. 

One  square  foot  steam  pipe  for  every  120  feet  of  wall,  roof,  or 
ceiling. 

One  cubic  foot  of  boiler  is  required  for  every  2,000  cubic  feet  of 
space  to  be  heated. 


316 


GAS  ENGINEER'S  POCKET-BOOK. 


One  horse-power  boiler  is  sufficient  for  50,000  cubic  feet  of  space. 
Steam  should  be  about  112°. 

Heating. — 1  square  foot  of  pipe  surface  heated  to  200°  will  cause 
an  average  of  58°  of  heat  in  150  cubic  feet  of  air. 

Heating  Rooms. — 1  square  foot  of  pipe  surface  is  required  for  80 
cubic  feet  of  space  ;  1  cubic  foot  of  boiler  is  required  for  1.500  cubic 
feet  of  space ;  1  horse-power  boiler  is  sufficient  for  40,000  cubic  feet 
of  space. 

Allow  1  square  foot  pipe  surface  per  120  feet  wall  and  ceiling  space 
for  steam  heating. 

Allow  1  cubic  foot  for  every  1 ,300  square  feet  wall  surface  when 
once  warmed,  but  for  preliminary  heating  about  four  times  this 
amount  is  required,  which  also  allows  for  ventilation. 

The  length  of  piping  required  to  represent  1  square  foot  of  heating 
surface — 

36  inches  of  1  inch  wrought  iron  tubing  to  1  square  foot. 


28 
24 
20 
16 
13 
10 


1! 

2 

2i 
3 
4 


cast  iron 


The  allowance  would  be  18  square  feet  of  heating  surface  for  living 
rooms,  13  feet  for  bedrooms,  and  20  feet  for  halls  for  each  1,000 
cubic  feet  of  air  in  the  place  to  be  warmed.  1  inch  main  will  supply 
up  to  70  square  feet.  1£  inch  main  will  supply  up  to  150  square  feet. 
1£  inch  main  will  supply  up  to  300  square  feet.  2  inch  main  will 
supply  up  to  600  square  feet.  2J  inch  main  will  supply  up  to  800 
square  feet.  (Gr.  Chasser.) 


Percentage  of  Heat  Evolved  by  Open  Grates  and  Close  Stoves. 
(D.  K.  Clark.) 


Open  Grates. 

Close  Stoves. 

Heat  carried  up  the  chimney 
Radiated  and  conducted  heat  absorbed 
by  the  walls          .    -i'  '.        .-'       .     .  ' 
Heat  lost  by  radiation  and  conduction 
externally,  and  heat  lost  by  imper- 
fect combustion        .... 

43  per  cent. 
42         „ 

15 

24 
54 

22 

100 

per  cent. 

!) 
» 

100 

One  pound  of  coal  burnt  in  an  ordinary  grate  requires  for  its 
combustion  300  cubic  feet  of  air  having  a  temperature  of  620°  F. 
(Sir  Douglas  Galton.) 


HEATS    OF    FIRES. 


317 


Quantity  of  soot  given  off  by  a  coal  fire  burning  house  coal  of 
different  qualities.  —  The  amount  is  said  to  be  on  the  average  6£  per 
cent,  of  the  carbon  in  coal. 

Bunsen  burners  should  be  made  on  the  same  lines  as  injectors,  as 
the  rush  of  the  gas  at  the  nipple  causes  the  intake  of  air  at  the  side 
holes.  The  full  -pressure  of  the  gas  should  therefore  be  allowed  to 
proceed  to  the  nipple. 

To  Prevent  Stoves  from  Busting.  —  Melt  3  parts  lard  with  1  part 
powdered  resin  ;  add  black  lead  if  desired.  Brush  over  in  a  thin  coat. 


Best  Heats  for  Cooking. 


Roasting  pork 
Veal         . 
Pastry  .        . 
„     puff 


320°  F. 
320° 
320° 
340° 


Beef      . 
Mutton    . 
Meat  pies 


310°  F. 

300° 

290° 


Heats  of  Different  Fires. 

Heat  of  a  common  wood  fire  =     800°  to  1,140°  F. 
.,        charcoal  fire  =  2,200°  (about). 

„        coal  fire  =  2,400° 


Number  of  Grammes  of  Water  Raised  1°  through  Equal  Thickness  of 

Plate. 


Copper 

Zinc 

Iron 


918 
292 
156 


Tin 

Steel 

Lead 


150 

from  111  to  62 
.      79 


Breeze  mixed  with  tar  (40  gallons  to  the  ton)  does  not  produce  a 
smoky  fuel,  and  retains  its  shape. 

The  pitch  used  for  agglomerating  briquettes  must  not  have  had  its 
binding  qualities  destroyed  by  the  removal  of  its  anthracene  and 
heavy  oils.  A  suitable  pitch  should  soften  at  75°  C.,  melt  at  100°  to 
120°  C.,  remain  hard  at  the  normal  temperature,  and  be  capable  of 
carriage  in  bulk.  Its  fracture  should  be  dead  black,  conchoidal,  clean 
and  soft,  without  being  greasy  to  the  touch  ;  and  the  edges  should  not 
splinter  when  bitten  by  the  teeth.  So  prepared,  coke  would  burn  as 
freely  as  bituminous  coal.  (W.  Colquhoun.) 

Tar  for  making  pavements  should  be  heated  until  converted  to 
pitch  that  will  harden  on  cooling.  If  overheated  it  loses  its  elas- 
ticity, and  pavements  made  with  it  disintegrate  rapidly.  Refuse 
materials,  such  as  clinkers,  may  be  employed,  and  the  pitch  should 
be  run  straight  from  the  boiler  on  to  them,  well  mixed  and  laid  and 
rolled  at  once.  One  barrel  of  boiled  tar  will  make  50  cubic  feet  of 
pavement. 


318 


GAS  ENGINEER'S  POCKET-BOOK. 


Proportions  of  Tar  Concrete. 


Aggregate  .... 
Sharp  sand  (clean) 
Coal  tar      .... 
Lias  lime  or  Portland  cement 


7  parts. 

2  „ 
6  „ 
2  . 


For  the  manufacture  of  tar  paving  it  is  usual  to  heat  the  stones 
over  an  iron  plate,  and  then  add  tar  which  has  been  heated  in  open 
boilers,  and  the  lighter  oils  evaporated  at  about  1 94°  F.  The  time 
taken  for  this  heating  varies  from  four  to  twelve  hours,  as  it  is  not 
desirable  that  the  creosote  oils  should  be  distilled  off. 


Briquettes. 

Good  coal  briquettes   contain   5   per  cent,   of  pitch  if  strongly 
pressed,  or  7  to  8  per  cent,  if  pressed  with  inferior  or  hard  pitch. 


Balloons. 

The  lifting  power  of  a  balloon  is  the  difference  between  its  weight 
and  that  of  the  air  which  it  displaces. 

1  cubic  foot  air  weighs  approximately  -075  Ib.  or  1-29   ozs. 

1          „          hydrogen  „  -005  „     „     -089    „ 

1          „          coal  gas  „  -043  „     „     -35      „ 

1          „         air  heated  to  200°  C.  weighs  approximately  -042  Ibs. 

Therefore  lifting  power  of  coal  gas  =  '075  -  -043  =  -032   Ib.   for 
each  cubic  foot  contained  in  the  balloon. 

The  lifting  power  of  hydrogen  equals  GO  to  70  Ibs.  per  1,000  cubic 
fest,  that  of  coal  gas  being  about  32  Ibs. 


Comparative  Cost  per  Horse  power  per  Hour.     (Herr  C.  Korte.) 


Size  of  Motor  (horse-power).  | 

i 

I 

1 

2 

3 

d. 

4 
d. 

6 

Class  of  Motor. 

Hours 
daily. 

d. 

d. 

d. 

d. 

d. 

Gas  motor  (gas  at  3s.  4d.  j 

5 

7-92 

5-76 

3-72 

2-88 

2-52 

2-40 

2-28 

per  1,000  cubic  feet)       .  1 
Hydraulic  motor  (water  at  ) 
6M.   per    1,000  gallon  sH 
90  Ibs  j 

10 

5 
10 

5-76 

12-12 
10-56 

4-08 

10-80 
9-84 

2-64 

9-72 
9-12 

2-88 

9-00 

8-64 

2-04 

1-92 

1-80 

Electric      motor     (Berlin  J 

5 

8-88 

7-22 

5-88 

5-04 

4-68 

— 

— 

tariff)      .        .        .        .1 

10 

7-56 

6-48 

5-40 

4-80 

4-44 

— 

— 

Compressed     air     motor  J 

5 

15-00 

11-64 

8-40 

6-96 

6-00 

5-40 

4'32 

(Paris  tariff)      .        .     .  1 

10 

13-08 

10-44 

7-68 

6-48 

5-84 

5-16 

4-08 

Steam  motor,  with  coal  at  f 

5 

— 

— 

4-20 

2-88 

2-40 

2-04 

i-so 

12s.  6d.  per  ton             .1 

10 

— 

— 

2-88 

2-04 

1-68 

1-44 

1-32 

Steam  motor,  with  coal  at  j 

5 





4-92 

3-48 

3-00 

2-82 

2-28 

20s.  per  ton        .        .     .  1 

10 





3-48 

2-52 

2-16 

1-92 

1-G8 

Hot  air  motor,  with  coal  at  f 

5 

11-28 

6-72 

4-44 

3-36 

— 

— 

— 

12s.  6d.  per  ton                 ( 

10 

6-48 

4-08 

2'76 

2-16 

~ 

~ 

WET  METERS. 


319 


Extract  from  Hartley's  "Analysis  of  Gas." 

A  wet  meter  becomes  slow  to  a  certain  limited  degree  in  registration  when 
worked  above,  arid  fast  to  a  lesser  degree  when  worked  below  its  proper 
speed,  as  will  be  seen  from  the  following  results  of  careful  experiments : 
Meter  working  at  2.\  times  its  proper  speed    .     rO2  per  cent.  slow. 
„  ,,  its  proper  speed        .         .     .     correct. 

i  of  its  proper  speed     .         .     '28  per  cent.  fast, 
i  -cjft 

it  •>•>  To       "  »  »       •  •      •  »  » 

It  is  therefore  manifest  that  the  surest  way  to  attain  accuracy  will  be  to 
always  work  the  test  meter  at  its  proper  speed,  and  only  use  it  with  meters 
as  liii'ge,  or  larger  than  itself.  The  closer  the  relation  is  in  capacity  between 
the  test  meter  and  the  one  under  test,  the  more  accurate  will  be  the  results  ; 
as  a  rule,  the  former  meter  should  not  be  less  (or,  at  all  events,  much  less) 
than  one-tenth  of  the  capacity  of  the  latter. 

In  testing  large  meters  at  one-fifteenth  or  one-twentieth  of  their  speed, 
I  have  found  it  necessary  to  increase  the  allowance  at  times  to  as  much  as 
1  and  1}  .per  cent.  No  definite  rule  can  be  laid  down,  however,  because 
the  extent  of  disturbance  of  the  water  level  in  the  measuring  wheel  depends 
partly  upon  the  relative  areas  of  the  wheel  and  meter  case,  and  these  vary 
with  almost  every  meter. 

It  may,  however,  be  safely  assumed  that  if  a  station  meter,  to  which 
kind  the  application  of  a  test  meter  should  be  generally  restricted, 
registers  2£  per  cent,  fast  at  one-tenth  of  its  speed,  it  will  be  correct 
within  the  meaning  of  the  act  at  full  speed.  The  best  plan  would  of  course 
be  to  keep  them  within  closer  limits. 

Use  a  constant  water  level  gauge  in  station  meters,  and  keep  a  con- 
tinuous stream  of  water  running  in. 

A  groaning  station  meter  may  be  quieted  by  pumping  in  below  the  water 
line  a  hot  water  solution  of  soft  soap  and  oil. 

Wet  Meters. 


Lights. 

Capacity  of 
Drum. 
Cubic  Feet. 

Capacity  per 
Hour. 
Cubic  Feet. 

Diameter  of 
Inlet. 

Dimensions  over  all. 

Back 
Height.   Width.       to 
Front. 

Inches. 

Inches.  Inches.  Inches. 

2 

•083 

12 

£ 

15$  X  10    X    7£ 

3 

•125 

18 

£ 

17    X  12i  X    8f 

5 

•25 

30 

| 

18|  X  15i  x    g| 

10 

•5 

60 

1 

21i  X  19i  X  121 

15 

•75 

90 

1 

24    X  2l|  X  14$ 

20 

1 

120 

H 

26|  x  23|  X  15§ 

30 

1-5 

180 

H 

28|  X  26*  X  17| 

50 

2-5 

300 

28|  X  26f  X  22£ 

60 

3 

360 

H 

28f  X  26J  X  25 

80 

4 

480 

2 

33f  X  30J  X  28| 

100 

5 

600 

2£ 

38$  X  35*  X  29$ 

150 

7-5 

900 

3 

40    X  39    X  31f 

200 

10 

1,200 

3 

43|  X  42£  X  32£ 

250 

12-5 

1,500 

\ 

46    X  45$  X  32f 

300 

15 

1,800 

ill 

46    X  45$  X  45| 

400 

20 

2,400 

Q 

49|  X  48|  X  48£ 

500 

25 

3,000 

0 

51^  X  50^  X  62£ 

600 

30 

3,600 

/  H 

51^  X  50J  X  65i 

320 


GAS  ENGINEER'S  POCKET-BOOK. 


Dry  Meters. 


Lights. 

Mameter  of 
Inlet. 

Capacity  per 
Revolution. 

Capacity 
per  Hour. 

Dimensions  over  all. 

Back 
Height.    Width.       to 
Front. 

Inches. 

Cubic  Feet. 

Inches.   Inches.   Inches. 

2 

| 

•083 

12 

HI  X  101  x     71 

3 

| 

•125 

18 

15*  X  Hi  X    8 

5 

•16 

30 

17    X  13    X    8| 

10 

I4 

•3 

60 

19i  X  15    X  10£ 

15 

1 

•416 

90 

21i  X  16    X  11|- 

20 

H 

•5 

120 

24     X  18i  X  12£ 

30 

if 

•83 

180 

25|  X  20|  X  14 

40 

if 

1-25 

240 

29f  X  23    X  17 

50 

if 

1-428 

300 

32i  x  251  X  21 

60 

if 

1-6 

360 

33i  X  27^  x  21 

80 

2 

2-5 

480 

38J  X  31i  x  22 

100 

2 

2-857 

600 

40|  X  32i  x  23i 

120 

*i 

3-3 

720 

46i  x  35*  X  26 

150 

3 

0 

5-0 

900 

48£  X  38    X  27 

200 

3i 

-g 

6-6 

1,200 

56f  X  42i  x  29 

250 

3* 

i 

7-3 

1,500 

56    X  45    X  32i 

300 

4 

g 

8-3 

1,800 

62    X  48    X  37 

400 

4 

•§ 

12-5 

2,400 

70    X  52    X  40 

500 

5 

s 

14-285 

3,000 

73|  X  58    X  46 

600 

6 

"v 

22-222 

3,600 

77    X  58    X  50 

800 

7 

J 

25-0 

4,800 

88    X  61    X  52 

1000 

8 

C 

33-333 

6,000 

90    X  64    X  54 

Standard  Sizes  of  Unions  for  Connecting  Gas  Meters. 
(Board  of  Trade  Standards  Department,  1902.) 


Size  of  Meter 
No.  of  Lights. 

Diameter  of 
Outside  Thread 

of  Boss. 

No.  of  Threads 
per  inch. 

Diameter  of  Boss 
Opening  to  Admit 
Short  Shank  of 
Lining. 

Depth  of 
Thread. 

Inches. 

Inches. 

Inches. 

2&3 

0-98 

18 

0-6(i 

0-36 

5 

1-15 

12 

0-82 

0-55 

10 

1-45 

11 

1-05 

0-57 

20 

1-82 

11 

1-40 

0-57 

30 

2-05 

11 

1-55 

0-57 

50 

2-25 

11 

1-75 

o-r>7 

60 

2-45  ' 

11 

2-00 

0-57 

80  &  100 

3-02 

11 

2-30 

0-57 

PREVENTING  METERS  FREEZING. 


321 


Meters. 

Theoretical  capacity  of  meters  to  pass  gas  is  6  feet  per  hour  per 
light,  though  in  practice  larger  quantities  can  be  passed. 

All  meters  should  be  fixed  perfectly  level. 

The  meter  which  is  correct  at  a  low  pressure  would  be  found  to  be 
Slow  at  a  high  pressure. 

In  America  the  average  tests  of  dry  meters  in  one  town  was  £  per 
cent,  slow,  and  in  another  town  |  per  cent.  slow. 

Dry  meters  are  liable  to  absorb  the  illuminants  of  the  gas  on  the 
leathers  which  are  always  oily.  Even  the  water  in  the  photometer 
meter  may  have  a  thin  stratum  of  oil  on  the  surface  which  will  some- 
times absorb  the  illuminants,  and  it  ought,  therefore,  to  be  washed 
out  occasionally,  and  filled  only  with  distilled  water  having  about  2 
per  cent,  of  pure,  glycerine  in  it. 

To  prevent  wet  meters  from  freezing,  pack  horse  manure  round 
them,  or 

Turn  off  main  cock  and  light  a  jet  in  house  to  consume  the  pressure 
in  the  pipes,  unscrew  plug  and  pour  in,  say,  two  table-spoonfuls  of 
glycerine  (for  a  three-light  meter),  allow  a  few  minutes  for  the 
glycerine  to  come  to  the  surface,  and  then  shut  off  cock  in  house  and 
turn  main  cock  on  again. 

10  per  cent,  glycerine  freezes  at  30°  F.,  20  per  cent,  at  271°  F., 
30  per  cent,  at  21°  F.,  40  per  cent,  at  0°  F.  (Veitch  Wilson.) 

Glycerine  is  said  to  have  the  effect  of  reducing  the  illuminating 
power  of  the  gas  when  used  with  water  in  a  gas  meter. 

Mixture  used  in  E.A.  Hydraulic  Jacks  to  Prevent  Freezing. 

Methylated  spirits     7  gallons.  /\                  Area"  Diamr' 

Distilled  water     .     3£     „  /-.—A  ••« 7-854  - -3165 

Mineral  oil       .     .      i     •, 

Carbonate  of  soda  250  grains.  /. \ 15-708  =    '447 


A  governor  cone  should  be 
heavy  enough  to  prevent 
oscillation,  and  a  parabolic 
curve  of  a  length  equals  twice 
the  diameter  (see  drawing). 

To  force  gas  down,  say  a 
mine,  a  jet  of  water  may  be 
sprayed  into  the  top  of  pipe, 
and  will  cause  an  injector 
action  according  to  the  quan- 
tity of  water  in  use. 

Area  of  governor  bell  some- 
times taken  at  20  times  area 
of  base  of  cone. 


\    23-502 


•548 


....31-416  =  '6325 


.  39-77 


•712 


...  47-624  =    -779 


54-978=    -837 


...62-832  =    '895 
70-686  =  -9485 
...78-54    --1-0 


G.B. 


322 


GAS  ENGINEER'S  POCKET-BOOK. 


TESTING, 
Elementary  Bodies, 


Symbols. 

Combining 
Weights. 

Specific 
Gravity. 

Melting  Points. 
C. 

Aluminium 

Al 

27-0 

2-67 

Antimony     .     . 

Sb 

120-0 

6-71 

425° 

Arsenic 

As 

74-9 

f    5-67 
j    5-9 

Barium         .     . 

Ba 

136-8 

4-0 

Beryllium  .        . 

Be 

9-2 

Bismuth        .    . 

Bi 

208-0 

9-8 

270° 

Boron 

B 

11-0 

2-69 

Bromine        .     . 

Br 

79-75 

2-966 

Cadmium  . 

Cd 

111-9 

8-65 

315° 

Caesium        .     . 

Cs 

133-0 

Calcium     . 

Ca 

39-9 

1-58 

Carbon  .         .     . 

C 

11-97 

Cerium 

Ce 

139-9 

Chlorine        .     . 

Cl 

35-37 

Chromium 

Cr 

52-1 

7-3 

Cobalt  .         .     . 

Co 

58-6 

f    7-81 
\    8-5 

Copper 

Cu 

63-1 

8-93 

1090° 

Didymium    .     . 

D 

142-0 

Erbium 

E 

166-0 

Fluorine        .    . 

F 

19-1 

Gallium     . 

G 

69-8 

— 

+  30° 

Gold      .         .     . 

Au 

196-2 

19-3 

Hydrogen  . 

H 

1-0 

•06926 

Indium  .         .    . 

In 

113-4 

7-42 

Iodine        .        . 

I 

126-53 

4-95 

Iridium         .     . 

Ir 

192-7 

22-38 

Iron  .        .        . 

Fe 

55-9 

7-8 

1050°  to  1600° 

Lanthanum  .     . 

La 

138-0 

Lead  .        .        * 

Pb 

206-4 

11-35 

334° 

Lithium       ,„...  . 

Li 

7-01 

0-594 

Magnesium 

Mg 

24-3 

1-74 

Manganese 

Mn 

55-0 

8-01 

Mercury        .     . 

Hg 

199-8 

13-59593 

at  0°  C.  -  40° 

Molybdenum 
Nickel        . 

Mo 

Ni 

95-8 
58-6 

8-8 

Niobium        .     . 

Nb 

94-0 

Nitrogen    . 

N 

14-01 

•97137 

Osmium         .     . 

Os 

198-6 

22-5 

21-4° 

Oxygen 

O 

15-96 

1-10563 

Palladium     .     . 

Pd 

106-2 

11-4 

Phosphorus 

P 

30-96 

1-77 

AIR,    GAS,    AND    WATER, 
Elementary  Bodies—  continued. 


323 


Symbols. 

Combining 
Weights. 

Specific 
Gravity. 

Melting  Points. 
C. 

Platinum       .     . 

Pt 

194-5 

21-5 

Potassium  . 

K 

39-04 

0-865 

62-5° 

Rhodium       .     . 

Kh 

104-1 

12-1 

Rubidium  . 

Rb 

85-2 

1-52 

Ruthenium    .     . 

Ru 

103-5 

12-29 

Scandium  . 

Sc 

44-0 

Selenium       .     . 

Se 

78-0 

4-3 

Silver 

Ag 

107-66 

10-5 

1000° 

Silicon  .        .     . 

Si 

28-0 

Sodium 

Na 

22-99 

0-974 

95-60° 

Strontium     .     . 

Sr 

87-2 

2-54 

Sulphur     . 

S 

31-98 

2-00 

Tantalum      .     . 

Ta 

182-0 

Tellurium  . 

Te 

125-0 

6-25 

Terbium        .     . 

Tb 

148-5 

Thallium   . 

Tl 

203-6 

11-85 

Thorium        .     . 

Th 

231-5 

Tin    . 

Sn 

117-8 

7-29 

235° 

Titanium       .     . 

Ti 

48-0 

Tungsten  . 

W 

184-0 

Uranium        .     . 

U 

240-0 

18-4 

Vanadium 

V 

51-2 

Ytterbium     .     . 

Yb 

173-2 

Yttrium     . 

Y 

89-0 

Zinc      .         .     . 

Zn 

65-1 

6-8  to  7-2 

433° 

Zirconium  . 

Zr 

90-0 

(In  the  case  of  gases,  air  =  1. 

,  solids,  water  =  1.) 

Air,  Gas  and  Water. 

Pressure  of  atmosphere  =  14-7  Ibs.  per  square  inch  =  2116-8  Ibs. 
per  square  foot. 

Pressure  of  atmosphere  equals  29-9  inches  of  mercury  at  sea  level. 
„  „  „     33-9  feet  of  water  at  sea  level. 

29  cubic  feet  of  coal  gas  equals  1  Ib.  approximately. 

1  cubic  foot  of  air  at  62°  F.  equals  -076  Ibs. 

Gas  or  air  expands  s^ud  of  its  bulk  at  32°  F.  for  each  degree  F. 

Water  is  at  its  maximum  density  at  39-2°  F.  (4°"  C.)  and  expands 
ith  part  of  its  bulk  on  freezing. 

Centre  of  pressure  -jfrds  depth  from  surface. 

1  litre  of  fresh  water  =1  kilogramme  = -001  cubic  metre  =  '22 
gallons  =  2'2  Ibs.  =  '0353  cubic  feet  =  61  cubic  inches. 

1  ton  of  fresh  water  equals  1,016  kilogrammes,  1-0165  cubic  metres, 
1,016  litres. 

1  ton  of  fresh  water  =  35'9  cubic  feet  =  224  gallons. 

1  cubic  metre  of  fresh  water  =  1,000  litres  =  1,000  kilogrammes. 
35-316  cubic  feet  =  220  gallons  =  2,200  Ibs. 

1  cubic  foot  of  fresh  water  =  62-425  Ibs.  =  -557  cwts.  =  -028  tons. 

Y2 


324 


GAS    ENGINEERS    POCKET-BOOK. 


1  cubic  foot  of  fresh  water  equals  6-24  gallons,  or  salt  water  64  Ibau 

1  cubic  inch  of  fresh  water  =  '03612  lbs.  = -003612  gallons. 

1  gallon  of  fresh  water  =  10  Ibs.  =  '16  cubic  feet. 

1  cwt.  of  fresh  water  =  T8  cubic  feet=  11*2  gallons. 

Head  of  water  in  feet  equals  pressure  in  Ibs.  per  square  inch  X  2'30T, 

Pressure  in  Ibs.  per  square  inch  equals  height  in  feet  X  '4335. 

Pressure  of  a  Column  of  Water  per  Square  Inch  and 
per  Square  Foot  in  Lbs. 


Head. 

Pressure  per 
Square  Inch. 

Pressure  per 
Square  Foot. 

Head. 

Pressure  per 
Square  Inch. 

Pressure  per 
Square  Foot. 

Inches. 

Lbs. 

Lbs. 

Feet. 

Lbs. 

Lbs. 

m 

•260 

25 

10-82 

1562-4 

1 

•520 

30 

12-99 

1874-9 

1-041 

35 

15-16 

2187-4 

JL 

1-562 

40 

17-32 

2499-8 

JL 

2-083 

45 

19-49 

2812-3 

i_ 

2-604 

50 

21-65 

3124-8 

tio 

3-124 

55 

23-82 

3437-3 

3-645 

60 

25-99 

3749-8 

.8. 

4-166 

65 

28-15 

4062-2 

JL 

4-687 

70 

30-40 

4374-7 

I10 

•0362 

5-208 

75 

32-48 

4687-2 

2 

•0723 

10-416 

80 

34-65 

4999-7 

3 

•1085 

15-624 

85 

36-82 

5312-2 

4 

•1446 

20-833 

90 

38-98 

5624-6 

5 

•1808 

26-040 

95 

41-15 

5937-1 

6 

•217 

31-248 

100 

43-31 

6249-6 

7 

•253 

36-457 

110 

47-64 

6874-6 

8 

•289 

41-666 

120 

51-98 

7499-5 

9 

•325 

46-872 

130 

56-31 

8124-5 

10 

•362 

52-08 

140 

60-64 

8749-4 

11 

•398 

57-29 

150 

64-97 

9374-4 

12 

•434 

62-5 

200 

86-63 

13124 

Feet. 

250 

108-29 

16249 

2 

•86 

125-0 

300 

129-95 

19374 

3 

1-30 

187-5 

350 

151-61 

22499 

4 

1-73 

250-0 

400 

173-27 

26248 

5 

2-16 

312-5 

450 

194-92 

29373 

6 

2-59 

375-0 

500 

216-58 

32498 

7 

3-03 

437-5 

600 

259-90 

38748 

8 

3-46 

500-0 

700 

302-22 

45622 

9 

3-89 

562-5 

800 

346-54 

52496 

10 

4-33 

624-9 

900 

389-86 

58746 

15 

6-49 

937-4 

1000 

433-18 

64996 

20 

8-66 

1249-9 

To  Bend  Glass  Tubes.     (Spon.) 

If.  a  sudden  bend  is  wanted,  heat  only  a  small  portion  of  the  tub* 
to  a  dull  red  heat,  and  bend  it  with  the  hand  held  at  the  opposite  ends. 
If  the  bend  is  to  be  gradual,  heat  an  inch  or  two  of  it  in  length 


•  SATURATED   HYDROCARBONS. 


325 


previous  to  bending  it.  If  a  gradual  bend  on  the  one  side  and  a 
sharp  one  on  the  other,  as  in  retorts,  a  little  management  of  the  tube 
in  the  flame,  moving  it  to  the  right  and  left  alternately  at  the  same 
time  as  it  is  turned  round,  will  easily  form  it  of  that  shape.  In 
bending  glass,  the  part  which  is  to  be  concave  is  to  be  the  part  most 
heated.  An  ordinary  gas  flame  is  quite  sufficient*  to  bend  glass  by, 
but  that  of  a  spirit  lamp  is  better. 

Series  I.— Paraffin  Series,  Marsh  Gas.     Saturated  Hydrocarbons. 

(E.  L.  Price.) 
Generic  Formulas  CnH2n  +  2. 


Illumina- 

Volume of 

Name  of 
Hydrocarbon. 

Formula. 

Boiling  Point 
F. 

Specific  Gravity 
Water  =1. 

ting  Power. 
Candles, 
per  5  Cubic 

Gas  from  1 
Gallon  GO°F. 
30  Inches 

Feet. 

Barometer. 

Methane    . 

CH4 

gas 

gas 

5-0 

Ethane      . 

C2H6 

gas 

gas 

35-0 

Propane     . 

C3H8 

gas 

gas 

53-9 

Butane 

^HIO 

34° 

•6 



37 

Pentane     . 

C5H12 

98°—  102° 

•626620-6  F. 



31 

Hexane 

^6^14 

156° 

•663620'6  F. 



27 

Heptane    . 

CfHje 

209° 

•70032°  F. 

— 

25 

Octane 

CgHig 

258° 

.719320  F. 



22 

Nonane  '   . 

C9H2Q 

297° 

.728560-5  F. 



20 

Decane 

CioH22 

331°—  334° 

•  739560.5  F. 



18 

Endecane  . 

CllH24 

356°—  359° 

•  765610  F. 



17 

Dodecane  . 

Ci2H26 

392°_395° 

.757640.4  F. 

— 

16 

Series  II. — Olefine  Series,  Saturated  Hydrocarbons.     (E.  L.  Price.) 
Generic  Formula  CnH2n. 


Name  of 
Hydrocarbon. 

Formula. 

Boiling  Point 
F. 

Specific  Gravity 
Water  =1. 

Illumina- 
ting Power. 
Candles, 
per  5  Cubic 
Feet. 

Volume  of 
Gas  from  1 
Gallon  60°F. 
30  Inches 
Barometer. 

Ethylene  . 
Propylene  . 
Butylene   . 
Pentylene  . 
Hexylene  . 
Heptylene. 
Octylene    . 

C2H4 
C8H6 
C4H8 

QHio 
C6H12 

C?Hi4 
CeHje 

gas 
gas 
gas 
91°—  108° 
154°—  158° 
205° 
.  257° 

gas 
gas 
gas 
•655M°  F. 
•699320  F. 

•739630.5  F. 

.723620.6  F. 

68-54 
123-05 

33 
30 

27 
23 

Ordinary  coal  gas  of  15  to  16  candle  power  contains  about  2  per 
cent,  benzene. 

The  effect  of  washing  gas  with  mineral  oil  of  '840  specific  gravity 
is  to  reduce  the  illuminating  power  of  the  gas  by  about  50  per  cent. 

The  stability  of  nearly  all  hydrocarbons  is  destroyed  when  subjected 
to  temperatures  above  2,000°  F.  (B.  H.  Thwaite.) 


326 


GAS  ENGINEER'S  POCKET-BOOK. 


Bromide  of  potassium  or  concentrated  sulphuric  acid  will  absorb 
unsaturated  hydrocarbons,  but  does  not  affect  in  diffused  daylight  the 
gaseous  members  of  the  saturated  hydrocarbons. 

A  piece  of  rag  moistened  with  a  mixture  of  terebene,  linseed  oil, 
and  turpentine,  and  rolled  into  a  ball,  rose  in  temperature  from  20°  C. 
to  87°  C.  in  the  first  hour,  and  began  to  fume  ;  and  in  the  next  hour 
increased  to  310°  C.,  fuming  strongly  ;  half-an-hour  later  the  rag  burnt 
at  a  temperature  of  360°  C.  (T.  Wilton.) 

Corks  freshly  cut  have  been  found  to  contain  an  appreciable 
quantity  of  ammonia,  and  may  cause  errors  in  gasworks  analysis. 

Elastic  Force  or  Tension  of  Aqueous  Vapour  in  Inches  of  Mercury. 


Temp. 

Temp. 

Force. 

Force. 

Temp. 

Temp. 

Force. 

Force. 

Fahr. 

Cent.        Inches. 

M.m. 

Fahr. 

Cent. 

Inche^ 

M.m. 

32°0 

0° 

•1-81 

4-6 

67 

19-4 

•662 

16-8- 

33 

0-55 

•188 

4-8 

68 

20-0 

•685 

17-391 

34 

1-1 

•196 

5-0 

69 

20-5 

•709 

17-9 

35 

1-65 

•204 

5-2 

70 

210 

•733 

18-6 

36 

2-2 

•212 

5-4 

71 

21-65 

•758 

19-25 

37 

2-75 

•220 

5-6 

72 

22-2 

•784 

19-9 

38 

3-3 

•229 

5-8 

73 

22-75 

•811 

20-55 

39 

3-85 

•238 

6-05 

74 

23-3 

•839 

21-3 

40 

4-4 

•248 

6-3 

75 

23-85 

•868 

21-95 

41 

5° 

•257 

6-534 

76 

24-4 

•897 

22-7 

42 

5-5 

•267 

6-75 

77 

25-0 

•927 

23-5 

43 

6-1 

•278 

7-0 

78 

25-5 

•958 

24-3 

44 

6-6 

•288 

7-3 

79 

26-05 

•990 

25-05 

45 

7-15 

•299 

7-55 

80 

26-6 

1-023 

25-9 

46 

7-7 

•311 

7-9 

81 

27-15 

1-057 

26-75 

47 

8-25 

•323 

8-15 

82 

27-7 

1-092 

27-6 

48 

8-8 

•335 

8-5 

83 

28-25 

1-128 

28-45 

49 

9-45 

•348 

8-85 

84 

28-8 

1-165 

29-4 

50 

10° 

•361 

9-165 

85 

29-45 

1-203 

30-55 

51 

10-55 

•374 

9-5 

86 

30-0 

1-242 

31-548 

52 

11-11 

•388 

9-9 

87 

30-55 

1-282 

53 

11-65 

•403 

10;25 

88 

3M 

1-324 

54 

12-2 

•418 

10-6 

89 

31-65 

1-366 

55 

12-75 

•433 

10-95 

90 

32-2 

1-410 

56 

13-3 

•449 

11-4 

91 

32-75 

1-455 

57 

13-85 

•460 

11-8 

92 

33-3 

1-501 

58 

14-45 

•482 

12-25 

93 

33-85 

1-548 

59 

15° 

•500 

12-7 

9t 

34-4 

1-597 

60 

15-55 

•518 

13-15 

95 

35-0 

1-647 

61 

16-05 

•537 

13-55 

96 

35-5 

1-698 

62 

16-06 

•556 

14-1 

97 

36-05 

1-751 

63 

17-15 

•576 

14-55 

98 

36-6 

1-805 

64 

17-7 

•596 

15-1 

99 

37-15 

1-861 

65 

18-3 

•617 

15-7 

100 

37-7 

1-918 

66 

18-9 

•639 

16-2 

WEIGHT   OF   AQUEOUS   VAPOUR. 


327 


Volume  of  1  Ib.  Air  at  Atmospheric  Pressure  equals  14-7  Ibs.  per 
Square  Inch. 


Tempera- 
ture. 

Volume 

Tempera- 
ture. 

Volume. 

Tempera- 
ture. 

Volume. 

Degrees 
Fahr. 

Cubic  Feet. 

Degrees 
Fahr. 

Cubic  Feet. 

Degrees 
Fahr. 

Cubic  Feet. 

0 

11-583 

230 

17-362 

525 

24-775 

32 

12-387 

240 

17-612 

550 

25-403 

40 

12-586 

250 

17-865 

575 

26-031 

50 

12-840 

260 

18-116 

600 

26-659 

62 

13-141 

270 

18-367 

650 

27-915 

70 

13-342 

280 

18-621 

700 

29-172 

80 

13-593 

290 

18-870 

750 

30-428 

90 

13-845 

300 

19-121 

800 

31-685 

100 

14-096 

320 

19-624 

850 

32-941 

120 

14-592 

340 

20-126 

900 

34-197 

140 

15-100 

360 

20-630 

950 

35-453 

160 

15-803 

380 

21-131 

1,000 

36-710 

180 

16-106 

400 

21-634 

1,250 

42-990 

200 

16-606 

425 

22-262 

1,500 

49-274 

210 

16-860 

450 

22-890 

2,000 

61-836 

212 

16-910 

475 

23-518 

2,500 

74-400 

220 

17-111 

500 

24-146 

3,000 

86-962 

To  Find  the  Weight  of  Aqueous  Vapour  in  Air. 

(1)  Weigh  calcium  chloride  in  a  small  basin  ;  cover  the  basin  with 
a  bell  jar.     Suppose  the  bell  jar  contains  1  cubic  foot  of  air,  weigh  the 
basin  after  some  time.     The  increase  in  weight  will  be  the  amount  of 
aqueous  vapour  in  1  cubic  foot  of  air. 

(2)  Place  calcium   chloride,    or    pumice-stone  dipped   in   strong 
sulphuric  acid,  in  tubes  (both  substances  absorb   aqueous   vapour). 
Weigh  the  tubes  ;  then  pass  20  gallons  of  air  through  them.     The 
increase  in  weight  equals  the  amount  of  aqueous  vapour  in  20  gallons. 
This  forms  a  chemical  hygrometer. 

The  maximum  pressure  of  a  vapour  depends  upon  temperature  and 
the  kind  of  liquid  used. 

At  different  temperatures  the  maximum  pressure  of  water  vapour 
has  been  carefully  determined. 


Temperature  C. 

Pressure  inMilli- 
metres. 

Temperature  C. 

Pressure  in  Milli- 
metres. 

—32° 

0-320 

15° 

12-699 

—20 

0-927 

18 

15-357 

—10 

2-093 

20 

17-391 

0 

4-600 

50 

91-981 

4 

6-097 

70 

233-093 

10 

9-165 

90 

525-450 

12 

10-457 

100 

760-000 

328  GAS  ENGINEER'S  POCKET-BOOK. 

Weight  of  I  cubic  foot  dry  air  at  60°  F.  and  30  inches  press  of 
mercury  is  about  537  grains. 


Composition  of  the  Atmosphere. 

By  volume  oxygen   =  20*8,  by  weight  =  23 
„  nitrogen  =  79-2,         „         =77 

It  also  contains  a  little  ammoniacal  gas,  and  from  3  to  6  parts  in 
10,000  of  its  volume  of  CO2. 

Carbon  dioxide  in  atmosphere  equals  about  4  volumes  per  10,000  of 
air. 

1  cubic  foot  water  at  ordinary  temperature  and  pressure  dissolves 
1  cubic  foot  C02. 

The  higher  the  temperature,  the  greater  the  amount  of  aqueous 
vapour  held  in  suspension  in  the  gas. 

The  corrected  volume  of  dry  gases  for  both  temperature  and 
pressure  equals 

observed  volume  X  observed  pressure  X  17-33 
observed  temperature  +  460 

because  the  product  of  the  volume  and  pressure  of  a  gas  is  pro- 
portional to  the  absolute  temperature. 

The  density  of  liquid  air  is  910.     (Dewar.) 

100  cubic  inches  oxygen  weigh  34-29  grains. 
100      „          „      hydrogen  „       2'14      „ 

Minimum  Quantity  of  Oxygen  that  will  Support  Combustion. 
(Professor  Clowes.) 

Paraffin  flame 16-6  per  cent,  oxygen. 

Candle       „ 15'7        „  „ 

Methane    „ 15-6        „  „ 

CO  „ 13-35      „ 

Coal  gas    „ 11'35      „  „ 

Hydrogen  „ 5'5        „  „ 

The  quantity  of  moisture  in  coal  gas  saturated  20°  C.  and  760 
millimetres  equals  2  per  cent,  which  has  the  effect  of  reducing  the 
illuminating  power  3' 3  per  cent. 

1  grain  hydrogen  occupies  46'73  cubic  inches. 

To  Find  the  Speed  of  Sound  in  Air. 

Let  A  =  distance  between  the  observer  and  the  cannon  in  feet. 
B  =  seconds  that  elapse  between  seeing  the  flash  and  hearing 

the  report. 
C  as  feet  per  second. 


EXPLOSIVE   MIXTURES. 


329 


Force  of  Explosive  Mixtures  of  Air  and  Glasgow  Coal  Gas, 
(Dugald  Clerk.) 


Mixture. 

Maximum  Pressure 
of  Explosives 

Time  of  Explosion. 

Gas. 

Air. 

Square  Inch. 

1  volume 

13  volumes 

52 

0-28  seconds. 

1       » 

11       » 

63 

0-18       „ 

1       „ 

9       ,, 

69 

0-13       „ 

1       „ 

7       „ 

89 

0-07       „ 

1       „ 

5       „ 

96 

0-05       „ 

Heat  of  explosion  of  gun  cotton  =  2650°  C.  =  4802°  F. 
Explosive  mixtures  are  more  readily  kindled  upwards  by  a  flame 
placed  below  them,  than  downward  by  one  placed  above  them. 


Limiting  Explosive  Mixtures  of  Gases  and  Air, 
(Professor  Clowes.) 


Upward 
Kindling. 

Downward  Kindling. 

Per  cent.  Gas. 

Per  cent.  Gas. 

Per  cent.  Gas. 

Methane 

5  to  13 

6 

11 

Coal  gas 

5  to  28 

9 

22 

Water  gas 

9  to  55 

Hydrogen 

5  to  72 

CO 

13  to  75 

Ethylene 

4  to  22 

Coal  gas,  horizontal  tube,  10-3  per  cent,  to  23  per  cent.  (L.  T.  Wright.) 

10-3  per  cent,  of  coal  gas  (18'75  candles  and  -45  specific  gravity 
(air  equals  1))  and  89*7  per  cent,  air  is  the  lowest  limit  of  an  explosive 
mixture. 

23  per  cent,  coal  gas  as  above  and  77  per  cent,  air  is  the  highest 
limit.  (L.T.Wright.) 

The  limiting  percentages  of  explosive  gaseous  mixtures  are  : — For 
methane,  5  and  13  ;  for  hydrogen,  5  and  72 ;  for  carbon  monoxide, 
13  and  75  ;  for  ethylene,  4  and  22  ;  for  water  gas,  9  and  55  ;  for  coal 
gas,  5  and  28.  It  was  also  proved  that  many  mixtures  which  were 
outside,  but  close  to,  the  above  limits,  and  which  could  not  be  fired 
from  above  could  be  fired  from  below. 

An  exceedingly  small  quantity  of  coal  dust  in  air  is  sufficient  to 
cause  an  explosion. 


330 


GAS  ENGINEER'S  POCKET-BOOK. 


Expansion  by  Heat  and  Melting  Points  (F.). 


Expansion. 

Melting  point  in 
degrees  F. 

1° 
1  Part  in 

180° 
1  Part  in 

Fire  brick  .... 

365,220 

2,029 

Granite           .        .      from 

187,560 

1,042 

...    to 

228,060 

1,267 

Glass  rod       .        .        .     . 

221,400 

1,230 

„     tube. 

214,200 

1,190 

„     crown  .                 .     . 

211,500 

1,175 

„     plate 

209.700 

1,165 

Platina  

208,800 

1,160 

4,593 

Marble,  granular  white  dry 

173,000 

961 

„            „            „   moist 

128,000 

711 

„            „       black  com- 

pact .... 

405,000 

2,250 

Antimony      .        .         .     . 

166,500 

925 

883 

Cast  iron    .... 

162,000 

900 

1,920  to  2,800 

Slate      

173,000 

961 

Steel  

151,200 

840 

2,370  to  2,550 

„    blistered       .        .     . 

159,840 

888 

„     untempered 

167,400 

930 

„    tempered  yellow  .     . 

131,400 

730 

„    hardened  . 

146,800 

816 

„    annealed       .        .     . 

147,600 

820 

Iron,  rolled 

149,940 

833 

3,000  to  3,500 

„    soft  forged    .        .     . 

147,420 

819 

„    wire  .... 

146,340 

813 

Bismuth         .         ... 

129,600 

720 

500 

Gold,  annealed  . 

123,120 

684 

2,058 

Copper  .        .          average 
Sandstone  .... 

104,400 
103,320 

580 
574 

1,975 

Brass     .        .          average 

97,740 

543 

1,853 

„      wire. 

94,140 

523 

Silver    

95,040 

528 

1,866 

Tin    .        .         .      average 

87,840 

488 

443 

Lead     .        .        .  average 

62,180 

351 

612 

Pewter       .... 

78,840 

438 

Zinc  (most  of  all  metals)  . 

61,920 

344 

680  to  772 

White  pine    .        .        .     . 

440,530 

2,447 

LBS.  WATER  HEATED  AND  COo  PRODUCED. 


331 


Lbs.  Water  Heated  and  C0.2  Produced  from  Various  Gases. 
(Letheby.) 


Per  Ib. 

Lbs.  of  Water  Heated, 

O 

Air 

CO3 

Per 

Re- 

Viti- 

Pro- 

Per  Ib. 

Cubic  ' 

Per  Ib. 

quired. 

ated. 

duced. 

Foot. 

O  used. 

Cubic 
Feet. 

Cubic 
Feet. 

Cubic 
Feet. 

Lbs. 

Lbs. 

Lbs. 

H  

93-4 

467 



62,030 

329 

7,754 

Marsh  gas         .        .     . 

47-2 

826 

23-6 

23,513 

996 

5,878 

Olefiant  gas  . 

40-5 

878 

27-0 

21,344 

1,585 

6,225 

Propylene         .         .     . 

40-5 

878 

27-0 

21,327 

2,376 

6.220 

Butylene 

40-5 

878 

27-0 

21,327 

3,168 

6,220 

Acetylene         .         .     . 

36-3 

909 

29-1 

18,197 

1,251 

5,914 

Benzole 

36-3 

909 

29-1 

18,197 

3,860 

5,915 

C02  

6-7 

371 

13-5 

4,325 

320 

7,569 

CS2       . 

14-9 

689 

5-0 

6,120 

1,239 

4,845 

H2S  . 

16-7 

630 

— 

7,444 

671 

5,271 

Cyanogen 

14-5 

435 

14-5 

6,712 

925 

5,142 

Coal  gas  (common)  .     . 

37-5 

618 

17-6 

21,060 

650 

6,816 

„       „     (cannel) 

31-0 

698 

220 

20,140 

760 

6,503 

Wood  spirit      .         .     . 

25-3 

422 

11-8 

9,547 

819 

6,363 

Lbs.  Water  Heated  and  C02  Produced  from  Various  Substances. 

(Letheby.) 


Per  Ib. 

Lbs.  of  Water  Heated, 
1°F. 

O 

Air 

C03 

Per 

Re- 

Viti- 

Pro- 

Per  Ib. 

Cubic 

Per  Ib. 

quired 

ated. 

duced. 

Foot. 

O  used. 

Cubic 

Feet. 

Cubic 
Feet. 

Cubic 

Feet. 

Lbs. 

Lbs. 

Lbs. 

Alcohol         .        .        . 

24-6 

533 

16-4 

12,929 

1,597 

6,195 

Camphine         .        .    . 

38-9 

880 

27-8 

19,573 

7,134 

5,942 

Carbon 

31-0 

943 

31-5 

14,544 



5,447 

Ether       .                 .     . 
Paraffin        , 

30-9 
40-5 

664 

878 

20-4 
27-0 

16,249 
21,327 

3,217 

6,158 
6,220 

oil      . 

40-5 

878 

27-0 

21,327 



6.220 

Rape  oil        ... 

38-7 

801 

24-3 

17,752 



6J23 

Sperm  oil         .         .     . 

38-7 

801 

24-3 

17,230 



6,088 

Spermacetti  . 

37-0 

815 

25-2 

17,589 



6.088 

Stearic  acid     .         .    . 

34-6 

783 

24-0 

17,050 



0,061 

Stearine 

34-4 

527 

14-2 

18,001 

— 

6,143 

Wax         .... 

37-7 

829 

25-6 

15,809 

— 

4,995 

332  GAS  ENGINEER'S  POCKET-BOOK, 

Temperature  of  Combustion.     (Letheby  and  Others.} 


Open  Flames. 

Closed  Vessel. 

InO. 

In  Air. 

InO. 

In  Air. 

H 

Degrees. 
14,510 

Degrees. 
5,744 

Degrees. 
19,035 

Degrees. 

7,852 

Marsh  gas         .         .     . 

14,130 

4,762 

18,351 

6,680 

Olefiant  gas 

16,535 

5,217 

21,344 

7,200 

Propylene         .        .     . 

16,522 

5,239 

21,327 

7,177 

Butylene 

16,522 

5,232 

21,327 

7,177 

Acetylene          .        .     . 

17,146 

5,142 

22,006 

7,009 

Benzole 

17,146 

5,142 

22,006 

7,009 

C02           .... 

12,719 

5,358 

16,173 

7.225 

CS2 

15,280 

4,314 

20,031 

5,917 

H2S           .... 

13,688 

4,388 

17,542 

6,026 

Cyanogen 

13,488 

5,028 

17,645 

6,167 

Coal  gas  (luminous)      . 

14,320 

5,228 

18,101 

7,001 

Cannel  gas    . 

14,826 

5,121 

19,046 

7,186 

Wood  spirit      .         .     . 

11,435 

4,641 

14,902 

6,347 

Alcohol 

13,305 

4,831 

17,223 

6,629 

Ether        .... 

14,874 

5,150 

19,225 

6,953 

Camphine 

16,271 

5,026 

20.953 

6,922 

Expansion  of  Liquids,  from  32°  to  212°  F.    Volume  at  32°  =  1. 


Liquid. 

Volume  at 
212° 

Expan- 
sion. 

Liquid. 

Volume  at 
212° 

Expan- 
sion. 

Alcohol  . 
Nitric  acid    . 
Olive  oil 
Turpentine    . 
Air    . 

M100 
1-1100 
1-0800 
1-0700 
1-374 

a 
£ 

A 
i 

3 

Sea  water 
Water       .    . 
Mercury 
Spirits  of  wine 

1-0500 
1-0466 
1-018 
1-110 

A 
* 
S 

a 

To  find  the  weight  of  water  that  can  be  evaporated  from  and  at 
212°  F.  in  Ibs.  per  Ib.  of  fuel— 

•15  {  o/0  of  0  +  (4-28  X  %  H)}  or, 

,  Total  heat  of  combustion 
966 

Coefficient  of  the  Expansion  of  Gases.    (Charles's  Law.) 


AH  gases  expand  ^rd  part  of  their  volume  for  every  degree  Centi- 
grade increase  in  temperature  above  0°  ;  or,  in  decimals,  0'00366B. 


FREEZING   POINTS. 


333 


Expansion  and  Weight  of  Water  from  32°  to  500°  F. 


Tempera-  1 
ture. 

Relative 
Volume  by 
Expansion. 

Weight 
of  1  Cubic 
Foot. 

Weight  of 
1  Gallon. 

H 

Relative 
Volume  by 
Expansion. 

Weight 
of  1  Cubic 
Foot. 

Weight  of 
1  Gal  on. 

Deg.  F. 

Lbs. 

Lbs. 

Deg.F. 

Lbs. 

Lbs- 

32 

1-00000 

62-418 

10-0101 

125 

1-01239 

61-654 

9-887 

35 

•99993 

62-422 

10-0103 

130 

1-01390 

61-563 

9-873 

39-1 

•99989 

62-425 

10-0112 

135 

1-01539 

61-472 

9-859 

40 

•99989 

62-425 

10-0112 

140 

1-01690 

61-381 

9-844 

45 

•99993 

62-422 

10-0103 

145 

1-01839 

61-291 

9-829 

46 

1-00000 

62-418 

10-0101 

150 

1-01989 

61-201 

9-815 

50 

1-00015 

62-409 

10-0087 

155 

1-02164 

61-096 

9-799 

52-3 

1-00029 

62-400 

10-0072 

160 

1-02340 

60-991 

9-781 

55 

1-00038 

62-394 

10-0063 

165 

1-02589 

60-843 

9-757 

60 

1-00074 

62-372 

10-0053 

170 

1-02690 

60-783 

9-748 

62 

1-00101 

62-355 

10-0000 

175 

1-02906 

60-665 

9-728 

65 

1-00119 

62-344 

9-9982 

180 

1-03100 

60-548 

9-711 

70 

1-00160 

62-313 

9-9933 

185 

1-03300 

60-430 

9-691 

75 

1-00239 

62-275 

9-9871 

190 

1-03500 

60-314 

9-672 

80 

1-00299 

62-232 

9-980 

195 

1-03700 

60-198 

9-654 

85 

1-00379 

62-182 

9-972 

200 

1-03889 

60-081 

9-635 

90 

1-00459 

62-133 

9-964 

205 

1-0414 

59-93 

9-611 

95 

1-00554 

62-074 

9-955 

210 

1-0434 

59-82 

9-594 

100 

1-00639 

62-022 

9-947 

212 

1-0466 

59-64 

9-565 

105 

1-00739 

61-960 

9-937 

250 

1-06243 

58-75 

9-422 

110 

1-00889 

61-868 

9-922 

300 

1-09563 

56-97 

9-136 

115 

1-00989 

61-807 

9-913 

400 

1-1 

54-25 

8-700 

120 

1-01139 

61-715 

9-897 

500 

1-2 

51-16 

8-204 

Freezing  Points. 


Substances. 

Bromine  freezes  at 
Oil  anise 

„  olive 

„  rose 
Quicksilver 
Water 


Centigrade.  Fahrenheit. 

,     —20°     =—40° 

10°    =      50° 

10°    =      50° 

15°    =      60° 

—39-4°  =  —39° 

0°    =     32° 


334 


GAS  ENGINEER'S  POCKET-BOOK. 


Melting  Points  and  Expansions  of  Metals. 


Metals. 

Specific 
Heat. 

Melting  Point. 

Coefficient  of 
Expansion. 

C. 

F. 

Per  Degree  F. 

Aluminium,  pure 

•231     | 

704  to 
899 

1,300  to 
1,650 

I  -00001235 

Antimony       .        .     . 

'0508  I 

432  to 
621 

810  to 
1,150 

1  -00000601 

Asphalt 



100 

212 

Bismuth          .        .     . 

•031 

264 

507 

•0000078 

Brass  .... 

•094 

899 

1,650 

•00001047 

Bronze    .        .        .     . 



921 

1,690 

Copper 
Gold,  standard       .     . 

•0951 
•095 

1,091 
1,180 

1,996 
2,156 

•000001 
•00000821 

„      pure  . 



1,250 

2,282 

Iron,  cast  (grey)    .    . 

•130 

1,124 

2,056 

•00000616 

„       „    (white) 

•129    • 

1,050  to 
1,100 

1,922  to 
2,012 

„     wrought        .    . 

•110 

1,600 

2,912 

•00000657 

Lead  .... 

•031 

324 

615 

•00001555 

Mercury          .         .     . 

•033 

39-4 

-39 

.  -00009984 

Nickel         . 

•109 

1,543 

2,810 

•00000695 

Platinum        .         .     . 

•038 

1,693 

3,080 

•00000493 

Palladium  . 



1,500 

2,732 

Silver     .... 

•057 

1,001 

1,834 

•00001063 

Steel,  hard          .         ) 
„     mild      .        .     } 

•117 

f  1,300 
1  1,400 

2,732 
2,552 

•00000695 
•00000672 

Tin      ...        . 

•057 

230 

444 

•0000121 

Zinc        .... 

•096 

401 

754 

•00001636 

Melting  Points  of  Solids. 


Substance. 

Melting  Points. 

Substance. 

Melting  Points. 

C. 

F. 

C. 

F. 

Butter 

33-0 

91 

Sodium  chloride 

776 

1,429 

Calcium  chloride 

726 

1,339 

„       sulphate 

865 

1,589 

C02   . 

— 

—108 

Spermaceti 

49 

120 

Ice 
Iodine 

0 
115 

32 

239 

Stearine     .    .    j 

43  to 
49 

109  to 
120 

Nitro-glycerine  . 

7 

45 

Sulphur     . 

112 

234 

Phosphorus 

44 

111 

Tallow  .        .     . 

99 

92 

Potassium  iodate 

560 

1,040 

Turpentine 

—10 

14 

„          iodide 

634 

1,173 

Wax,  bees'     .     . 

65 

150 

Silver  nitrate    . 

198 

389 

„      paraffin    . 

45 

114 

BOILING   POINTS. 


335 


Melting  Points  of  Alloys, 


Tin. 

Lead. 

Bismuth. 

Softens  at. 

Melts  at, 

Degrees  F. 

Degrees  F. 

5 

3 

8 

— 

202 

1 

1 

1 

— 

254 

2 

2 

1 



292 

4 

4 

1 

— 

320 

2 

1 





340 

4 

1 





365 

1 

1 

— 

365 

371 

6 

1 

— 



381 

2 

6 

— 

372 

383 

2 

7 



377-5 

388 

2 

8 

—  . 

395-5 

408 

1 

2 





441 

1 

3 

— 

— 

482 

1 

5 

— 

511 

Boiling  Points,  Latent  Heat  of  Evaporation,  and  Heat  from 
32°  F.  of  1  Ib. 


Boiling  Point. 

Latent 
heat  of 
Evapo- 
ration 
of  1  Ib. 

Volume  at 
32°  F.  =  1. 
Volume 
at  212°  F. 
equals. 

Total  heal 
from  32° 
F.  of  1  Ib. 

C. 

F. 

Alcohol      .... 

78 

173 

374 

1-110 

461-7 

Ammonia      .         ... 

60 

140 

Benzine     .... 

80 

176 

Bisulphide  of  carbon    .    . 

47 

116 

Bromine    .... 

63 

145 

Ether    

35 

95 

„      nitrous    . 

14 

57 

Iodine  

181 

347 

Linseed  oil        ... 

314 

597 

Mercury        .                .     , 

342 

648 



1-018 

Nitric  acid 





__ 

1-110 

Olive  oil        . 

315 

600 



1-080 

Paraffin     .... 

280 

536 

Petroleum     .        .        .    . 

158 

316 

Quicksilver 

350 

662 

Salt       

413 

775 

Sulphur     .... 

236 

447 

Sulphuric  ether     .        .     . 

38 

100 

175 



210-4 

Sulphurous  acid 

—10 

14 

157 

315 

124 

ro70 

256-6 

Water        .... 

100 

212 

965-2 

1-047 

1146-1 

„      sea      . 

101 

213-2 

— 

1-050 

„      saturated  brine 

108 

226 

Wood  spirit  .                 .     . 

66 

150 

475 



545-9 

Zinc  . 

1,040 

1,904 

— 

1-0029 

336 


GAS  ENGINEER'S  POCKET-BOOK. 


The  specific  heat  of  a  body  is  the  ratio  of  the  quantity  of  heat 
required  to  raise  that  body  1°  in  temperature,  compared  to  the 
quantity  of  heat  required  to  raise  an  equal  weight  of  water  from  39° 
to  40°  F. 

Specific  Heats. 


Acid  hydrochloric    . 

.     -600 

Petroleum 

o    -434 

Alcohol 

.     .     '659 

Phosphorus 

.     -2503 

Benzene    .         .        . 

.     -3932 

Quicklime 

.     -2169 

Brickwork   . 

.     .     -192 

Soda    .        .        •       f 

.     -2311 

Chalk       .         .    !    . 

.     -2148 

Stonework        .        .  ;. 

.     -197 

Carbon 

.     .     '2411 

Sulphur 

.     -2026 

Charcoal  . 

.     -2415 

Sulphuric  acid,  density  1 

•87  -3346 

Coal,  anthracite  . 

.     .     -2017 

»»                     ?>                 5>            ^ 

•30  '6614 

„     bituminous 

.     -2411 

Sulphate  of  lead 

.     -0872 

Coke    . 

.     •     '203* 

„         „  lime  .      {'. 

.     -1966 

Ether        .         .        . 

.     -521 

Turpentine       .        .  V 

.     '416 

Glass    . 

.     .     -1937 

Vinegar 

.     -92 

Graphite  . 

.     -2019 

Water  at  32°  F. 

.  1-0 

Ice       ... 

.     .     -504 

„       „  212°  F..       V 

.  1-013 

Magnesium  limestone 

.     -2174 

Wood,  average 

.     -550 

Marble 

.     .     -2129 

„      spirit 

.     -6009 

Olive  oil  . 

.     -3096 

* 

Increases  as  temperature  rises. 

The  atomic  specific  heat  of  carbon  is  expressed  by  the  following 
formula  :— From  0°  to  250°  C.,  it  is  C  =  1-02  +  0"0077£  ;  from  250° 
to  1,000°  C.,  it  is  C  =  3-54  +  0'0246£.  (MM.  Uchene  and  Biju-Duval.) 


Specific  Heats  of  Oases,  &c. 


Equal 
Pressure. 

Equal 
Volume. 

Equal 
Pressure. 

Equal 
Volume. 

Acetone  . 

0-4125 

0-8244 

Hydrogen 

3-4046 

0-2359 

Air      . 

0-2377 

0-2374 

H2S     . 

0-2432 

0-2857 

Alcohol   . 

0-4534 

0-7171 

Hydrochloric 

„       vapour 

0-4513 

0-3200 

acid 

0-1845 

0-2333 

Ammonia    .     . 

0-5083 

0-2966 

Light  carburet- 

Benzole   . 

0-3754 

1-0114 

ted  hydrogen 

0-5929 

0-4683 

Binoxide  of  ni- 

Marsh gas  .     . 

0-5929 

0-3277 

trogen      .     . 

0-2315 

0-2406 

Nitrogen  . 

0-2440 

0-2370 

Bromine  .   ...   . 

0-0555. 

0-3040 

Nitric  acid  .     . 

0-2317 

0-2406 

Chlorine      .    . 

0-1210 

0-2962 

„      oxide    . 

0-2262 

0-3447 

CO  . 

0-2479 

0-2370 

Oxygen   . 

0-2182 

0-2405 

C0a     . 

0-2164 

0-3307 

Steam,saturated 

— 

0-3050 

CSa  . 

0-1570 

0-4140 

„     gas    .     . 

0-4750 

0-2984 

Chloroform.     . 

0-1567 

0-6461 

Sulphurous  an- 

Ether 

0-4810 

1-2296 

hydride 

0-1553 

0-3414 

Ethylene     .     . 

0-4040 

0-4106 

Turpentine  .     . 

0-4160 

2-3776 

FREEZING    MIXTURES. 


337 


Specific  Heat  of  Water  at  Different  Temperatures, 


Heat  to  Raise 

Heat  to  Raise 

Tempera- 
ture, F. 

Specific  Heat. 

1  Ib.  Water 
from  32°  F.  to 
given  Tempera- 

Tempera- 
ture, F. 

Specific  Heat. 

1  Ib.  Water 
from  32°  F.  to 
given  Tempera- 

ture. 

ture. 

Degrees. 

Units. 

Degrees. 

Units. 

32 

I'OOOO 

o-ooo 

248 

1-0177 

217-449 

50 

1-0005 

18-004 

266 

1-0204 

235-791 

68 

1-0012 

36-018 

284 

1-0232 

254-187 

86 

10020 

54-047 

302 

1-0262 

272-628 

104 

1-0030 

72-090 

320 

1-0294 

291-132 

122 

1-0042 

90-157 

338 

1-0328 

309-690 

140 

1-0056 

108-247 

356 

1-0364 

328-320 

158 

1-0072 

126-378 

374 

1-0401 

347-004 

176 

1-0089 

144-508 

392 

1-0440 

365-760 

194 

1-0109 

162-686 

410 

1-0481 

384-588 

212 

1-0130 

180-900 

428 

1-0524 

403-488 

230 

1-0153 

199-152 

446 

1-0568 

422-478 

Freezing  Mixtures. 


Fall  in  Temperature. 

Degrees 
Cold  pro- 
duced. 

Nitrate  of  ammonia    . 
Water     .... 

1  part) 

1     „    J 

From  +  50°  to  +    4°  F. 

46°  F. 

Dilute  sulphuric  acid  . 
Snow      .        ... 

2     „ 
3     „ 

„      +  32    „    -  23  „ 

55  „ 

Muriate  of  lime  . 
Snow       .         .        .     . 

»      +  20   „    -  48  „ 

68  „ 

Phosphate  of  soda 

9     „ 

Nitrate  of  ammonia    . 

6     „ 

ii      +  50   „    -  21  „ 

71  „ 

Dilute  nitric  acid 

^     » 

Common  salt  .         .     . 

1     „ 

From  any  temperature 

Snow  or  powdered  ice 

2     „ 

to  -  5°  F. 

Common  salt 
Nitrate  of  ammonia    . 
Snow  or  powdered  ice 

5     „ 

5     „ 
12     „ 

From  any  temperature 
to-25°F. 

Sulphate  of  sodium     . 
Dilute  nitric  acid  .     . 

3     „    ) 
2     „    J 

From  10°  C.  to  -  18°  C. 

Phosphate  of  sodium  . 

6     „    i 

Dilute  nitric  acid  ' 

5     „    I 

ii          »      ii   —  ^"  » 

Crystallized     calcium 

chloride  . 

10   „  I 

,,      ,,    -50  „ 

Snow      .        .        .     . 

7    „    J 

Water  (H20)  when  freezing  expands  from  1  volume  to  1-09. 
G.  E.  z 


338 


GAS   ENGINEERS   POCKET-BOOK. 


Expansion  of  Liquids  in  Volume  from  32°  to  212°. 


1.000  parts  of  water 
„      oil        ... 
„            „      mercury    . 
„            „      spirits  of  wine 
„            „      atmospheric  air 

become  1,046 
1,080 
„        1,018 
1,110 
„         1,376 

Latent  Heat  is  the  heat  absorbed  by  any  substance,  without  raising 
its  temperature,  in  changing  from  the  solid  to  the  liquid  state,  or 
from  the  liquid  to  the  gaseous  state. 


Latent  Heats  of  Fusion. 


Mercury 

Lead 

Sulphur 


2-8 
5-4 
9-4 


Bismuth 
Silver  . 
Water 


12-6 
21-1 

80-2 


Latent  Heat  Liquefaction. 


Water  at  39°  F 
Bismuth 
Lead  . 
Mercury 


142-65 

22-75 

9-67 

5-09 


Silver 

Tin 

Zinc. 


37-93 
25-65 
50-63 


Comparative  Powers  of  Solids  for  Conducting  Heat. 


Gold  . 
Platinum 
Silver 
Copper  . 
Brass 
Iron,  cast 
„     wrought 
Zinc 

1,000 
981 
973 
892 
749 
562 
374 
363 

Aluminium 
Tin 
Lead  . 
Marble       . 
Bismuth    . 
Porcelain 
Terra  Gotta 

305 

304 

180 

24 

18 

12 

11 


Eelative  Heat  Conductivity  of  Metals.    Silver  equals  1,000. 


Silver 

Gold      . 

Copper 

Mercury 

Aluminium 

Zinc 

Wrought  Iron 


1,000 
981 
845 
677 
665 
641 
436 


Tin     . 
Steel      . 
Platinum 
Cast  Iron 
Lead  . 
Antimony 
Bismuth 


422 
397 
380 
359 
287 
215 
61 


RADIATION    OF    HEAT, 


339 


Comparative  Powers  of  Solids  for  Absorbing  or  Radiating  and 
Reflecting. 


Reflecting. 

Absorbing. 

Silver,  polished   . 

97  per  cent. 

3  per  cent. 

Gold        .... 

95     ,       „ 

5     „      „ 

Copper 

93     ,       „ 

7 

1          »            >5 

Brass,  bright  polished 

93     ,       „ 

7 

•         5>           >5 

„      dead         „ 

89     ,       „ 

11        „           „ 

Speculum  metal      .    . 

86     ,       „ 

14     „      „ 

Tin      . 

85     ,       „ 

15     „      „ 

Steel,  polished        .     . 

83     „      „ 

17     „      „ 

Platinum,  sheet  . 

83         „            5, 

17     „      „ 

„         polished 

80     „     „ 

20     „      „ 

Zinc'    .... 

81     „     „ 

19     „      „ 

Mercury          .        .     . 

77     „      „ 

23     „      „ 

Iron,  wrought,  polished 

77     „      „ 

23    „      „ 

„     cast,              „      . 

75     „      „ 

25     „      „ 

Silver  leaf  on  glass     . 

73     „      „ 

27     .,      „ 

Ice  .        .        .        .     . 

15     „      „ 

85     „      „ 

Glass  .... 

10   „    „ 

90     „      „ 

Writing  paper        .     . 

2     „      „ 

98           •;              „ 

Water. 

o   „    „ 

100     „      „ 

Marble    .... 

2  to  7     „      „ 

98  to  93     „       „ 

Quantity  of  Heat  Lost  per  Square  Unit  of  Surface.     (Peclet.) 


Excess  of 
Temperature 

of  Gas 
over  Air. 
10°    . 
20° 
30°    . 
40°        . 
50°   . 


Loss  in 
Air. 

.       8    . 

.  18 

.  29    . 

.  40 

.  53    . 


Loss  in 
Water. 

88 

266 

5,353 

8.944 

13^37 


Effect  of  Mixing  Water  at  Different  Temperatures. 

1  Ib.  of  water  at  0°  C.  +  1  Ib.  of  water  at  16°  C.  equals  2  Ibs.  of 
water  at  8°  C. 

1  Ib.  of  water  at  0°  C.  +  1  Ib.  of  water  at  35°  C.  equals  2  Ibs.  of 
water  at  17-5°  C. 

1  Ib.  of  water  at  16°  C.  +  1  Ib.  of  water  at  35°  C.  equals  2  Ibs.  of 
water  at  25-5°  C. 

1  Ib.  of  water  cooling  from  16°  to  8°  raised  the  temperature  of  1  Ib. 
from  0°  to  8°. 


Convection  is  the  transference  of  heat  by  particles. 
Conduction  is  the  transmission  from  particle  to  particle. 


Z2 


340 


GAS  ENGINEER'S  POCKET-BOOK. 


British  Thermal  Unit  equals  quantity  of  heat  necessary  to  raise 
1  Ib.  pure  water  1°  F.  from  39-1°  to  401°. 

Calorie  equals  quantity  of  heat  necessary  to  raise  1  kilogramme 
pure  water  1°  C.  at  or  about  4°  C. 

B.  T.  TJ.  X  '252  =  Calories,  or  Calories  X  3*968  =  B.  T.  U. 

Joule's  Law  —1  B.  T.  D.  equals  772  foot  Ibs.  work  performed. 

Joule's  law  shows  that  the  quantity  of  work  required  to  raise  the 
temperature  of  1  Ib.  of  water,  weighed  in  vacuum,  from  60°  to  61°  F. 
equals  772*55  foot  Ibs.  at  sea  level  in  the  latitude  of  Greenwich  ; 
or  the  amount  of  work  that  is  converted  into  heat  by  raising  1  Ib.  of 
water  1°  C.  is  1,390  foot  Ibs.  (fths  of  772). 

Metals  all  possess  the  same  atomic  heat  =  6-4. 


To  convert  Fahrenheit  to  Centigrade 


5  fF    —  32^ 
-  —    - 


9  C. 

To  convert  Centigrade  to  Fahrenheit  -  —  f-  32  =  F. 


Comparison  of  the  Value  of  Coal  Gas  for  Motive  Power  and 
Lighting  at  Different  Candle  Powers.     (C.  Hunt.) 


Illuminating  Power 
of  Gas. 
Candles. 

Consumption  per 
I.H.P.  per  Hour. 
Cubic  Feet. 

Value  for  Motive 
Power. 

Value  for 

Lighting. 

11-96 

30-31 

1-000 

1-000 

15-00 

24-41 

1-241 

1-254 

17-20 

22-70 

1-335 

1-438 

22-85 

17-73 

1-709 

1-910 

26-00 

16-26 

1-864 

2-173 

29-14 

15-00 

2-020 

2-436 

Calorific  Value  of  Coal  Gas.     (T.  L.  Millar.) 


Illuminating  Power. 

Heating  Power  per 
Cubic  Feet. 

Glasgow   . 
Liverpool     .        .     . 
Kilmarnock 
Manchester  .         .     . 
Birmingham     . 
London        .        .     . 
Hoboken 
Berlin          .        .    . 

21  £  candles 
21         „ 
25 
16  and  19£  candles 
17*  candles 
16         „ 

813  heat  units 
770 
680 
654 
639 
624 
617 
549 

Theoretical  value  in  heat  units  of  1  cubic  foot  of  gas  of  16  candle 
power  equals  660  to  670  (1  Ib.  water  heated  1°  F.). 


HEAT   UNITS    FROM    DIFFERENT   SUBSTANCES. 


341 


The  number  of  heat  units  obtainable  in  practice  is  : — In  the  best 
bath  heaters,  about  600  ;  in  the  best  boiling  burners,  about  375. 
Effective  heating  duty  of  coal  gas  in  small  vessels  equals  300  to  620 

Effective  heating  duty  of  coal  gas  in  ordinary  flat-bottomed  vessels 
with  projecting  rivets  equals  520  units. 

Effective  heating  duty  of  coal  gas  in  domestic  pans  and  kettles 
equals  300  units. 

Effective  heating  duty  of  coal  gas  in  small  pans  and  kettles  equals 
150  units.  (T.  Fletcher.) 

15  candle  gas  gives  620  heat  units  per  cubic  foot. 
19          „  „     800         „  „ 

(N.  H.  Humphreys.) 

Carbon,  when  combined  with  hydrogen  to  form  defiant  gas  (C2H4) 
and  acetylene  (C2H2),  has  a  locked-up  heat  energy,  as  compared  with 
the  carbon  forming  marsh  gas  (CH^)  of  31,300  and  75,430  heat  units 
respectively  which  are  developed  as  light  and  heat  when  the  gases 
are  burned.  (YV.  Young.) 

Heat  Units  generated  by  Complete  Combustion. 


B.T.U. 

gross. 

Per  Ib. 
net. 

B.T.U. 

gross. 

Per  c. 

ft.  net. 

Calories. 

Hydrogen  (H) 

62535 

60791 

326-2 

272 

34462 

Carbon  (C)  to  C02     .         .     . 

14500 

12906 

— 

— 

7700 

„     co2.      .      . 

— 

2495 

— 

— 

1416 

CO  to  C02          .... 

4478 

4234 

323-5 

— 

24  OU 

Sulphur  (S)    . 

4102 

3916 

— 

— 

— 

Sulphuretted  hydrogen  (H2S) 

4940 

4420 

450 

403 

— 

Methane  (Marsh  Gas)  (CH4)  . 
Ethane  (C2H6)  .... 
Propane  (C3H8) 

23620 

21420 

1024 
1764-4 
2521 

919 

3087 

Butane  (C4rI10)          .         .     . 

— 

— 

3274 

— 

— 

Ethylene  (C2H4)    . 

21713 

20460 

1603 

1510 

— 

Propylene  (C8H6)       .         .     . 

21220 

19830 

2B77 

2242 

— 

Butylene  (C4H8)    . 

20900 

1970U 

3921 

2696 

— 

Acetylene  (C,H2)       .         .     . 

— 

— 

1476-7 

— 

— 

Benzene  (CGHC) 

17780 

17100 

3718 

3574 

— 

Coal  gas  (17  candles)         .     . 

— 

i  <;;><  KS 

650 

— 

— 

Water  gas       .... 

8200 

7500 

304 

330 

— 

Producer  gas      .         .         .     . 

— 

1897 

160 

— 

— 

„          water  gas 

— 

983 

— 

— 

— 

The  maximum  temperature  obtainable  by  the  combustion  of  C 
equals  about  5,000°  F. 

The  maximum  temperature  obtainable  by  the  combustion  of  H 
equals  about  5,800°  F. 


342  GAS  ENGINEER'S  POCKET-BOOK. 

One  ton  coal =  8,353,846-640  calories. 

10,000  cubic  feet  gas  .        .        .     .  =  1,635,000-000       „ 
An  average  Lancashire  coal  is  said  to  have  a  calorific  power  of 
13,890,  which  means  that  1  Ib.of  the  coal  would  raise  13,890  Ibs.  water 
through  1°  F.  of  temperature. 

Relative  calorific  intensity  of  coke  per  Ib.  =  2,114°  C. 
»  ,i  ,,  tar        „        =  2,486°  C. 

(F.  G.  Dexter.) 
Latent  heat  «>f  steam        .        .        .536  thermal  units 

„  water    ....      79         „          „ 

Maximum  heat  obtainable  by  air  blast      .        .     2,500° 

The  boiling  point  of  hydrogen  is  found  to  be  234*5°  below  zero. 
Benzene  or  benzol  (C6H6)  boils  at  81°  and  freezes  at  0°  C. 
Naphthalene  (C10Hft)  melts  at  80°  and  boils  at  217°  C. 
Anthracene  (C14Hi0)  melts  at  213°  and  boils  at  a  little  above  360°  C. 

To  prepare  Acetate  of  Lead  Test  Papers. 

Moisten  sheets  of  bibulous  paper  with  a  solution  of  1  part  sugar  of 
lead  in  8  or  9  parts  water  and  hold  each  sheet,  while  still  damp,  over 
the  surface  of  a  strong  solution  of  ammonia  for  a  few  moments. 

Such  papers  will  become  tinged  if  subjected  to  gas  containing 
O'OOl  per  cent,  by  volume  of  H2S  for  24  hours,  light  being  excluded 
during  that  time. 

To  make  Turmeric  Papers. 

Six  parts  methylated  spirit  to  1  of  turmeric  powder  by  weight,  to  be 
well  shaken  from  time  to  time  for  3  days.  Decant  clear  liquid  and 
soak  sheets  of  botanical  or  filtering  paper  in  it,  dry  and  keep  in  the 
dark.  The  papers  should  be  a  full  yellow  colour.  One  grain  or  more 
NH3  per  100  cubic  feet  will  cause  the  colour  to  change  to  brownish 
tint. 

To  make  Red  Litmus  Paper. 

Dissolve  1  oz.  powdered  blue  litmus  in  6  ozs.  cold  distilled  water 
and  shake  well,  allow  to  dissolve  and  filter,  add  gradually  dilute 
H2S04  until  it  is  changed  to  a  red  tint ;  soak  sheets  of  glazed  paper 
in  it  and  dry.  These  papers  turn  blue  when  exposed  to  gas  contain- 
ing NH3. 

To  make  Lime  Water. 

Dissolve  4  ozs.  caustic  lime  in  1  quart  water,  shake  occasionally, 
decant  the  clear  liquid  and  keep  it  free  from  C02. 

If  gas  containing  C02  is  bubbled  through  a  portion  of  above,  it 
forms  CaC03,  the  liquid  becoming  milky,  thus  : 

CaO  +  C0a  —  CaC03. 


TO   PREPARE   INDICATORS.  343 

If  still  clear,  after  bubbling  for  3  minutes,  the  gas  is  probably  quite 
free  from  C02. 

All  H2S  must  be  removed  from  the  gas  by  means  of  oxide  of  iron 
before  making  above  test. 

To  prepare  Litmus  for  Indicating  Acids  and  Alkalies. 

Digest  solid  litmus  in  hot  water  and  evaporate  to  a  certain  degree, 
add  a  small  quantity  acetic  acid.  Evaporate  again  and  add  methy- 
lated spirit.  Filter  the  precipitate  and  wash  with  spirit,  dissolve  with 
warm  water  and  add  a  small  quantity  nitric  acid.  Keep  exposed  to 
the  air  to  preserve  the  colour.  Free  C02  effects  the  change  in  colour 
of  the  solution. 

To  prepare  Cochineal  for  Analysis  of  Ammonia, 

Take  1  part  methylated  spirit  and  4  parts  water,  keep  at  a  gentle 
heat  for  some  hours  with  about  10  grammes  cochineal  powder  to 
every  1,000  cubic  centimetres  of  the  solution,  cool  and  decant  the 
clear  liquid.  Its  yellow  colour  is  changed  to  red  by  alkalies,  and  to 
yellow  again  by  mineral  acids  and  is  not  affected  by  C02. 

The  acid  must  be  added  to  the  alkali  solution  when  using  this 
indicator. 

To  prepare  Methyl-orange  for  estimating  Ammonia  in  Gas. 

Dissolve  1  gramme  of  methyl-orange,  in  powder,  in  methylated 
spirit  and  make  up  to  1  litre  with  a  solution  of  one  part  water  and 
one  part  methylated  spirit. 

The  colour  is  changed  to  yellow  by  alkalies  and  then  to  red  by 
acids  ;  it  is  not  affected  by  C02. 

To  prepare  Phenol-phthalein. 

Make  an  alcoholic  solution  which  should  be  colourless,  but  an 
alkali  causes  it  to  become  red,  and  this  is  again  destroyed  by  an  acid. 
Phenol-phthalein  is  affected  by  the  presence  of  ammonia  salts  or  C0a. 

Standard  Solution. 

For  testing  gas  liquor  (Will's  test) — 

125  cubic  centimetres  NH3  (specific  gravity  '880)  to  1  litre  H20. 

10  per  cent,  acid  (specific  gravity  of  strong  acid). 

/I -067  =  9-8  per  cent.  acid. 

\10  parts  to  90  of  water. 

10  per  cent,  acid  =  1064-4  specific  gravity. 

To  prepare  Standard  Acid  Solution  for  test  of  Ammonia. 

Measure  a  gallon  of  distilled  water  in  a  clean  earthenware  jar  or 
other  suitable  vessel.  Add  to  this  94  septems  of  pure  concentrated 
sulphuric  acid  and  mix  thoroughly.  Take  exactly  50  septems  of  the 
liquid  and  precipitate  it  with  barium  chloride  in  the  manner  prescribed 
for  the  sulphur  test.  The  weight  of  barium  sulphate  which  50 


344  GAS  ENGINEER'S  POCKET-BOOK. 

septems  of  the  test  acid  should  yield  is  13*8  grains.  The  weight 
obtained  with  the  dilute  acid  prepared  as  above  will  be  somewhat 
greater,  unless  the  sulphuric  acid  used  had  a  specific  gravity  below 
1'84.  Add  now  to  the  dilute  acid  a  measured  quantity  of  water, 
which  is  to  be  found  by  subtracting  13'8  from  the  weight  of  barium 
sulphate  obtained  in  the  experiment  and  multiplying  the  difference 
by  726.  The  resulting  number  is  the  number  of  septems  of  water  to 
be  added.  If  these  operations  have  been  accurately  performed,  a 
second  precipitation  and  weighing  of  the  barium  sulphate  obtainable 
from  50  septems  of  the  test  acid  will  give  nearly  the  correct  number 
of  13'8  grains.  If  the  weight  exceeds  13'9  grains,  or  falls  below  13-7 
grains  more  water  or  sulphuric  acid  must  be  added,  and  fresh  trials 
made  until  the  weight  falls  within  these  limits.  The  test-acid  thus 
prepared  should  be  transferred  at  once  to  stoppered  bottles  which 
have  been  well  drained,  and  are  duly  labelled.  (Metropolitan  Gas 
Keferees.) 

To  prepare  the  Standard  Solution  of  Ammonia. 

Measure  out  as  before  a  gallon  of  distilled  water,  and  mix  with  it 
20  septems  of  strong  solution  ammonia  (specific  gravity  0'88).  Try 
whether  100  septems  of  the  test  alkali  thus  prepared  will  neutralize 
25  of  the  test  acid,  proceeding  according  to  the -direction  given  sub- 
sequently as  to  the  mode  of  testing.  If  the  acid  is  just  neutralized 
by  the  last  few  drops,  the  test-alkali  is  of  the  required  strength  ;  but 
if  not,  small  additional  quantities  of  water  or  of  strong  ammonia 
solution  must  be  added,  and  fresh  trials  made,  until  the  proper 
strength  has  been  attained.  The  bottles  in  which  the  solution  is 
stored  should  be  filled  nearly  full  and  well  stoppered.  (Metropolitan 
Gas  Keferees.) 

To  prepare  Potassium  Hydroxide  for  determining  C0a. 

Use  commercial  stick  potash,  not  purified  by  alcohol,  dissolve  8  ozs. 
in  a  pint  of  distilled  water  for  careful  and  exact  tests,  but  for  ordinary 
work,  a  more  dilute  solution  may  be  used. 

To  prepare  Bromine  for  determining  the  Hydrocarbons. 

Make  an  aqueous  solution  of  bromine  almost  saturated.  Before 
measuring  the  absorption  the  vapour  of  the  bromine  must  be  removed 
by  potassium  hydroxide  solution. 

A  solution  of  bromine  in  potassium  bromide  is  sometimes  used. 

To  prepare  Cuprous  Chloride  Solution  for  determining  CO. 

For  the  hydrochloric  acid  solution,  place  100  grammes  of  precipi- 
tated cuprous  chloride  in  a  bottle  and  pour  on  500  cubic  centimetres 
of  concentrated  hydrochloric  acid,  into  which  put  some  copper  spirals 
so  as  to  reach  to  the  top  of  the  liquid. 

Sor  the  ammoniacal  solution,  place  40  grammes  of  precipitated 
cuprous  chloride  in  a  bottle  and  fill  up  with  400  cubic  centimetres 
of  water,  into  this  bubble  some  ammonia  gas,  made  by  boiling  some 


TO   PREPARE  NORMAL   SOLUTIONS.  345 

strong  ammonia  solution,  the  fumes  from  which  are  carried  into  the 
bottle  containing  the  cuprous  chloride,  until  the  latter  assumes  a  pale 
blue  colour,  then  make  the  solution  up  to  500  cubic  centimetres,  and 
carefully  stopper  the  bottle. 

To  prepare  Sulphuric  Acid  for  determining  the  Hydrocarbons. 

The  acid  to  be  used  must  be  strongly  fuming  acid  (Nordhausen) 
which  on  cooling  to  a  slight  degree  below  usual  temperatures,  deposits 
crystals  readily.  It  is  used  either  on  coke  balls  thoroughly  saturated 
or  in  absorption  pipettes  with  glass  balls  inside.  Before  measuring 
the  absorption,  the  acid  vapours  must  be  removed  by  potassium 
hydroxide  solution. 

To  prepare  Pyrogallic  Acid  Solution  for  determining  Oxygen. 

Dissolve  fresh  pyrogallic  acid  in  3  times  its  weight  of  water 
(distilled).  After  pouring  this  into  the  absorption  tube,  put  in  eight 
times  the  volume  of  caustic  potash  solution.  The  absorption  of 
oxygen  is  slow  and  requires  about  5  minutes'  agitation. 

To  prepare  Normal  Oxalic  Acid. 

This  solution  should  contain  63  grammes  per  litre.  Dissolve  this 
quantity  in  distilled  water  and  make  up  to  1  litre.  Test  against 
normal  alkali.  Do  not  use  this  acid  with  methyl-orange,  and  keep  it 
out  of  direct  sunlight. 

To  prepare  Normal  Hydrochloric  Acid. 

This  solution  should  contain  36'5  grammes  per  litre.  Dilute  strong 
hydrochloric  acid  with  distilled  water  and  make  it  of  1*10  specific 
gravity  at  60°  F.  Test  against  normal  solution  of  sodium  hydrate 
and  dilute  to  normal  strength. 

To  prepare  Normal  Sulphuric  Acid  Solution. 

This  should  contain  49  grammes  pure  H2S04  per  litre.  Add  strong 
sulphuric  acid  to  distilled  water,  and  when  cool  test  by  means  of 
standard  sodium  carbonate  solution,  and  add  water  to  reduce  to 
normal  strength.  When  the  solution  is  correct  an  equal  quantity  of 
the  acid  should  exactly  neutralize  an  equal  quantity  of  the  alkali. 

To  prepare  Normal  Solution  of  Sodium  Carbonate. 

The  solution  should  contain  53  grammes  pure  Na2C03  per  litre  and 
the  Na2C03  should  be  dissolved  in  the  water,  and,  when  at  normal 
temperature,  the  amount  made  up  to  the  exact  quantity  by  adding 
distilled  water. 

To  prepare  Normal  Sodium  Hydrate  Solution. 

This  solution  should  contain  40  grammes  per  litre.  Dissolve  about 
44  grammes  caustic  soda,  purified  by  alcohol,  in  distilled  water, 
recently  boiled  and  cooled, 


346 


GAS  ENGINEER'S  POCKET-BOOK. 


Or  use  25  grammes  clean  metallic  sodium  in  distilled  water.  Test 
with  normal  acid  solution  and  dilute  to  proper  strength.  Specific 
gravity  of  solution  50  grammes  per  litre  equals  1-05. 

25  septems  standard  acid  neutralize  1  grain  NH3. 
100        „  „          ammonia  contain  1  grain  NH3. 

Equivalent  Normal  Solutions. 
Nitric  acid .63  grams  per  litre. 


Anhydrous  carbonate  of  soda 
Sulphuric  acid 
Sodic  hydrate     . 
Hydrochloric  acid  . 
Ammonia    . 


53 

49 

40 

36-5 

17 


Degrees  of  Twaddell's  Hydrometer  compared  with  Specific  Gravity. 


Twaddell. 

Specific 
Gravity. 

Twaddell. 

Specific 
Gravity. 

Twaddell. 

Specific 
Gravity. 

Twaddell. 

Specific 
Gravity. 

0 

1-000 

6 

1-030 

13 

1-065 

19 

1-095 

1 

1-005 

7 

1-035 

13-4 

1-067 

20 

•100 

1-4 

1-007 

7-4 

1-037 

14 

1-070 

21 

•105 

2 

1-010 

8 

1-040 

15 

1-075 

21-6 

•108 

2-8 

1-014 

9 

1-045 

16 

1-080 

22 

•110 

3 

1-015 

10 

1-050 

16-6 

1-083 

23 

•115 

4 

1-020 

10-2 

1-052 

17-0 

1-085 

23-2 

•116 

4-4 

1-022 

11 

1-055 

18-0 

1-090 

24 

•120 

5 

1-025 

12 

1-060 

18-2 

1-091 

25 

•125 

5-8 

1-029 

Degrees  Twaddell  x  5  +  1' 000  equals  specific  gravity. 
Specific  gravity  -  1-QOO 
5 


Degrees  Twaddell. 


To  find  the  volume  of  air  required  to  chemically  combine  with  any 
fuel  to  support  complete  combustion  : — 

1-52  {  per  cent,  of  C+3  (per  cent,  of  H)— -4  (per  cent,  of  0)   } 

equals  cubic  feet  per  Ib.  fuel,  of  air  as  at  62°  F.  and  at  one  atmosphere. 

In  above  no  notice  is  taken  of  the  air  required  by  the  sulphur, 
which  is  only  nominal. 

To  find  the  volume  of  gaseous  products  on  complete  combustion  of 
1  Ib.  fuel  as  at  62°  F.  at  one  atmosphere. 

(1-52  X  per  cent,  of  C)  +  (5-52  X  per  cent,  of  H) 

To  find  the  weight  of  gaseous  products  on  complete  combustion  of 
lib.  fuel  as  at  62°  F.  at  one  atmosphere  : — 

(•126  x  per  cent,  of  C)  +  (-358  x  per  cent,  of  H) 


LOSS   OP   LIGHT   ON   MIXING   AIR   WITH    GAS. 


347 


To  find  the  total  heat  of  combustion  of  any  fuel  containing  C 
and  H:— 

145  {  per  cent,  of  C  +  (4-28  X  per  cent.  H)  j- 

The  richer  the  gas  the  greater  the  quantity  of  0  required  for 
complete  combustion. 

1  volume  gas  requires  5£  volumes  air  for  complete  combustion. 

Results  of  different  mixtures  of  Gas  and  Air  on  Light  given  by 
Incandescent  Burners.     (W.  Foulis.) 

Illuminating  Power 
Glasgow  Gas.  Air.  per  Cubic  Foot- 

1  .         .     .     7       .         .         .     .     13-0  candles. 

1         ...     5-8         ...     28-2 

1    .         .         .     .     4      .         .         .     .     17-3        „ 

With  gases  of  over  50  candle  power  the  addition  of  small  quantities 
of  0  increases  the  illuminating  power  by  combining  rapidly  with 
the  H  of  the  hydrocarbons  and  therefore  not  requiring  the  use  of  a 
similar  quantity  of  O  combined  with  N  from  the  air,  the  N  acting 
merely  as  a  diluent,  with  low  quality  gases  the  quantity  of  0  possible 
to  effect  an  increase  is  very  minute. 

The  addition  of  a  small  proportion  of  oxygen  to  coal  gas  was  found 
by  Dr.  P.  Frankland  to  sensibly  increase  the  illuminating  power,  but 
the  addition  of  even  a  small  quantity  of  nitrogen  materially  decreases 
it.  1  per  cent.  N  reduced  the  luminosity  1  per  cent. 

Loss  of  Light  by  the  addition  of  air  to  Coal  Gas.     (VVurtz.) 

Air.  Loss  of  Light. 

3-00 15-69  per  cent. 

4-96 23-83    „      „ 

11-71 41-46    „      „ 

16-18 57-53    „      „ 

25-00  ,  84-00    , 


Loss  of  Light  per  Cent,  by  Mixing  Air  with  Coal  Gas. 


Air,  per  cent  . 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

15 

20 

30 

40 

Loss  of  Light, 

per  cent. 

6 

11 

18 

26 

33 

44 

53 

58 

64 

67 

80 

93 

98 

100 

The  reason  CO2  is  a  more  harmful  substance  than  N  is  that  the  specific 
heat  of  C0a  is  nearly  half  as  much  again  as  that  of  N"  and  consequently 
the  amount  of  heat  taken  up  by  CO,  in  being  raised  to  the  temperature 
of  the  flame  is  greater  than  that  taken  up  by  nitrogen. 

One  per  cent.  C02  reducing  the  illuminating  power  about  4  to  5  per 
cent. 

C0a,  air,  N,  and  water  vapour,  cool  and  dilute  flames. 

H  and  CO  dilute  only. 

The  addition  of  N  to  pure  ethylene  reduces  luminosity  in  propor- 
tion to  its  volume,  but  probably  when  N  is  added  to  coal  gas  some  of 
the  tarry  vapours  are  carried  forward  by  it,  and  the  luminosity  is 
therefore  not  decreased  to  the  same  extent. 


348 


GAS  ENGINEER'S  POCKET-BOOK. 


Comparative  Duty  of  Different  Burners  with  16-candle  Gas. 

(Professor  Lewes.) 


Burner. 
Flat  flame,  No.  0  . 

>               )>               5>       J 

,        „        ,,2. 

Light  per 
Cubic  Foot 
of  Gas. 
.     .     0-59 
.     0-85 
.     1-22 

Burner. 

Flat  flame,  No.  6  . 
7 
>'    ..       M             " 

Ordinary  Argand 

Light  per 
Cubic  Foot 
of  Gas. 
.     .     2-15 
.     2-44 
2-90 

>        »         »    3 

>              >J              M      *  • 

,         „         „    5 

.     1-63 
.     .     1-74 

;  .^  '  '.     1-87 

Standard      „ 
Regenerative 

.     3-20 

.  :  .  10-00 

Efficiency  of  Incandescent  Burners  with  Different  Quality  Gases. 
(Foulis.) 


Ordinary  Burner  (Flat  Flame). 

Incandescent  Burner. 

Illuminating  Power 
Corrected  to 
5  Cubic  Feet 

Candles  per 
Cubic  Foot. 

Illuminating  Power 
Corrected  to 
5  Cubic  Feet. 

Candles   per 
Cubic  Foot. 

23-1 

4-6 

117-3 

23-40 

17-9 

3-6 

90-3 

18-07 

16-2 

3-2 

87-9 

17-59 

14-6 

2-9 

84-4 

16-89 

13-5 

2-7 

81-9 

16-39 

The  following  Table  gives  the    results  obtained  with  Edinburgh 
gas  when  consumed  from  various  burners  : — 

Five  cubic  feet  are  equal  to  :  — 

Candle  Power. 
Bray  No.  8     .        .        .        .        .         .     25-00 

Bray  "  Special "  No.  8        .         .         .     .     29-43 

Bray  Adjustable  „    g    .        ,        . 

5J  »        ]  • 


21-72 
26-66 
28-37 
30-39 
36-16 
36-76 
36-87 
28-00 
32-35 
18-12 
20-75 
25-00 
23-75 
28-57 
19-41 
53-30 
61-95 

(Professor  W.  I.  Macadam.) 
With  a  Union  jet  CH4  and  C2H0  are  non-luminous. 


Milne's  Old  Regulator  . 
Spon's  Deflector  and  No.  7  Bray 
Noleton  Duplex  (No.  0  Bray) 
Parkinson  Regulator  and  No.  7.  Bray 
Peeble's  Regulator,  No.  | 


Welsbach 


"    f 

Street  Burner 
;  S  "  Burner 
C" 


COMPOSITION   OF   COAL   GAS. 


349 


Average  Composition  of  London  Gas.    (Dr.  Letheby.) 


Common  Gas. 

Cannel  Gas. 

Twelve 

Twenty 

Candle. 

Candle. 

Hydrogen      

46-0 

27-7 

Light  carburetted  hydrogen     .         .     . 

39-5 

50-0 

Condensable  hydrocarbons  . 

3-8 

13-0 

Carbonic  acid  

0-6 

o-i 

Carbonic  oxide      

7-5 

6-8 

Aqueous  vapour        

2-0 

2-0 

O'l 

0.0 

0-5 

0-4 

100-0 

100-0 

Analysis  of  London  Gas  at  probably  12  Candle  Power. 
(Thwaite.) 


Unsaturated  hydrocarbons    . 
Benzol        .... 
Marsh  Gas      .... 
Carbon  anhydride 

CO 

H 

O 

N 


Per 
Cent. 
3-84 
1-04 
35-63 
1-41 
6-15 
47-73 
0-30 
3-90 


Analysis  of  Coal  Gas,  London.    (Lancet.} 


Benzene  (CaH6)       . 
Olefines  (C2H4) 
Carbon  monoxide  (CO)  . 
Hydrogen  (H)     . 
Methane  (CH4) 
Nitrogen  (N)      . 


By  Volume. 

0-55 

4-45 

7-80 

52-90 

31-80 

2-50 


By  Weight. 

3-98 
11-76 
20-00 

9-84 
48-00 

6-42 


Average  Composition  of  16  to  17  Candles  Caking  Coal  Gas. 

(L.  T.  Wright.) 

Per  Cent. 
Hydrocarbons  capable  of  absorption,  say 

(CnHm) 4 

Paraffins,  treated  as  Marsh  gas  (CH4) .    .  38 

CO 6 

H .  48  to  50 

N  2 


350 


GAS  ENGINEER'S  POCKET-BOOK. 


Electrical  Memoranda. 

A  "  volt"  is  the  standard  or  measurement  of  pressure. 

An  "  ampere  "  is  the  standard  of  quantity  or  measurement  of  the 
rate  of  flow. 

An  "  ohm  "  is  the  standard  of  resistance  offered  by  129  yards  of 
No.  16  copper  wire. 

A  "Watt-hour  r)  is  the  standard  of  pressure  x  amperes  x  hours. 

A  "  unit"  is  the  standard  of  kilowatt  hours  (1,000  Watt-hours)  and 
will  maintain  a  16  c.  p.  lamp  15  hours. 

A  unit  of  electricity  =  100  cubic  feet  gas  yielding  2£  candles  per 
cubic  foot  =  12  cubic  feet  gas  in  Kern  burner  =  8  cubic  feet  gas  in 
high  pressure  burner. 

4  Watts  will  produce  1  c.p.,  764  Watts  =  11.  H.P. 

Heat  from  an  incandescent  electric  16  c.  p.  lamp  is  one-twentieth 
of  an  equal  gas  light. 

1  unit  of  electricity  gives  as  much  heat  as  6  cubic  feet  gas. 

0*746  unit  of  electricity  required  to  develop  1  B.  H.P.  per  hour, 
practically,  however,  0'85  unit  of  electricity  is  nearer. 

Price  per  unit  x  1,000 =  equivalent  value  of  gas  per 

c.  ft.  required  to  give  240  c.  p.  hours         thousand  feet. 

Composition  of  London  Gas  Companies'  Coal  Gas. 
(Professor  Lewes.) 


South 
Metropolitan. 

Gas  Light 
and  Coke. 

Commercial. 

Hydrogen          .        .        .        ." 

52-22 

53-36 

52-96 

Unsaturated  hydrocarbons  .     . 

3-47 

3-58 

3-24 

Saturated  hydrocarbons    . 

34-76 

32-69 

34-20 

CO         

4-23 

7-05 

4-75 

C02    

0-60 

0'61 

0-75 

N           

4-23 

2-50 

5-10 

O           ;    >. 

0-49 

0-21 

o-oo 

Approximate  Analysis  of  London  Coal  Gas. 
(Professor  V.  B.  Lewes.) 


Unsaturated  hydro- 
carbons, C2H4 

Saturated  hydro- 
carbons, CflHa  . 

Saturated  hydro- 
carbons. CH. 

CO      .      '  . 

N 

sv  D; 


.  by  volume  52'0  per  cent.,  by  weight    9'6  per  cent 


3-0 
1-0 

34-0 
5-0 
4-5 

o-o 

0-5 


7-7 

7-1 

49-9 

12-8 

11-5 

O'O 

1-4 


The  illuminating  power  is  far  more  dependent  upon  the  mode  in 
which  the  C  is  combined  than  upon  the  actual  percentage  present  in 
the  gas.  (W.  Young.) 


COMPOSITION   OF    ILLUMINATING    GASES. 


351 


Composition  of  Coal  Gas  by  Volume. 


H    .        .        .  34  to  53  per  cent. 
CH4  marsh  gas  43  to  36       „ 
CO  .    6  to  2-7      „ 


0  and  C02     .    1  to  0-3  percent, 
C4He  defines  13  to  3-0      „ 
N  .    3  to  5-0 


Composition  in  100  Volumes.    (Sir  H.  Koscoe.) 


Illuminating 

N 

Power  in 
Candles  per  5 

H. 

CH4. 

CnH3n. 

CaH4. 

CO. 

0 

Cubic  Feet. 

Cannel  gas 

34-4 

25-82 

51-20 

13-06 

(22-08) 

7-85 

2-07 

Coal  gas 

13-0 

47-60 

41-53 

3-05 

(  6-97) 

7-82 

Average  Composition  of  Natural  Gas  in  America. 


H 

Marsh  gas 


.  =  22  per  cent. 
.  =  67 


Other  bodies  in  small  quantities=  11 

100 


Composition  of  Coal  Gas,  Water  Gas,  and  a  Mixture. 
(E.  G.  Love,  1889.) 


Coal. 

Water. 

Mixture. 

Hydrogen           .... 
Marsh  gas 
CO     
Ethylene       
Ethane      
Benzol  vapour       .         .         .     . 
CO2            
0  
N       

Specific  gravity  (calculated)     . 
Calorific  power,  heat  units 
Air  required  for  combustion  of 
1  Ib.  of  gas,  Ibs. 

39-78 
45-16 
7-04 
4-34 

2-04 
1-08 
0-06 
0-50 

29-16 
24-42 
28-33 
12-46 

0-78 
2-88 

0-21 
1-76 

34-47 
34-79 
17-685 
8-40 
0-39 
2-46 
0-54 
0-135 
1-13 

100-00 
0-4644 
19233-6 

14-70 

100-00 
0-6551 
13913-6 

10-22 

100-00 
0-5597 
16114-4 

13-08 

(Extract  from  paper  by  E.  G.  Love,  at  Baltimore,  U.S.A.,  1889.) 


352 


GAS  ENGINEEK'S  POCKET-BOOK. 


Comparative  Analysis  of  Coal  Gas  and  Carburetted  Water  Gas. 
(A.  E.  Broadberry.) 


Description  of  Gas. 

HaS. 

C03. 

Illumi- 
nants. 

o. 

CO. 

H. 

Marsh 
Gas. 

*Bal- 
ance. 

Unpurified  car- 

buretted  water 

gas  . 

0-4 

6-0 

8-8 

0-5 

27-4 

32-3 

20-5 

4-1 

Unpurified  coal 

gas  from  scrub- 

ber outlet 

1-4 

1-3 

2-3 

1-1 

5-2 

43-0 

37-1 

8-6 

Combined    gas, 

purified  equals 

35  per  cent.car- 

buretted  water 

gas 

— 

— 

4-8 

0-2 

13-8 

41-1 

32-7 

7-4 

*  Probably  N. 

Specific  gravity  of  combined  gases,  '5,  H2S  and  C02,  calculated  by 
explosion  and  absorption. 

Napthalene  is  a  white,  shining,  crystalline  substance,  fusing  at 
176°  F.,  and  boiling  at  423°  F.,  but  volatilizing  when  brought 
into  contact  with  steam.  It  is  not  soluble  in  water,  but  readily 
dissolves  in  alcohol,  chloroform,  naptha,  ether,  or  carbon  disulphide. 
When  napthalene  is  found,  the  condition  of  the  coal  should  first  be 
looked  after.  The  use  of  wet  coal,  particularly  if  slack,  should  be 
avoided. 

A  test  is  to  neutralise  the  liquor  with  dilute  sulphuric  acid.  If 
napthalene  be  present,  the  liquor  assumes  a  rose  colour,  and  the 
sulphate  solution  gives  off  the  peculiar  odour  distinctly  characteristic 
of  napthalene. 

Carbon  Monoxide  (CO)  is  colourless,  and  has  no  taste,  burns  with 
a  lambent  blue  flame  on  admixture  with  oxygen  and  forms  C02. 

Can  be  absorbed  by  a  solution  of  cuprous  chloride  (Cu2  C12). 

Carbonic  oxide  is  a  colourless  gas  which  burns  with  a  bright  blue 
flame  forming  C02,  2  or  3  per  cent,  in  the  air  may  prove  fatal,  it  has 
no  odour.  Specific  gravity  is  '968, 100  cubic  inches,  weighs  30  grains. 

Carbon  Dioxide  (C02)  is  colourless  and  has  no  smell,  and  is  formed 
whenever  carbon  is  burnt  in  excess  of  air  or  oxygen. 

Ethylene  or  Olefiant  Gas  (C2  H*)  is  colourless  and  of  a  sweet  taste, 
burns  with  a  smoky  luminous  flame  in  air,  explodes  loudly  when 
mixed  with  3  volumes  0  and  fired,  the  same  quantity  being  required 
to  cause  complete  combustion. 

Methane  or  Marsh.  Gas  (CH^)  is  colourless,  and  burns  with  a  non- 
luminous  flame,  is  tasteless,  and  has  no  odour  ;  1  volume  CH4  and 
3  volumes  0  explode  with  a  light  when  1  volume  O  remains. 

Marsh  gas  weighs  17'41  grains  per  100  cubic  inches.  Density 
is  -659. 


VALUES   OP   ILLUMINATING   GASES.  353 

Relative,  Calculated,  and  Found  Values  of  Gra&es. 
(Professor  V.  B.  Lewes.) 

Illuminating  Value. 
Calculated.  Found. 

Methane    .  8-4  5-2 

Ethane  .  .       35-0    .         .     .      35'0 

Ethylene  .  .        .      60-9         .        .      68'5 

Acetylene     ....     202-2     .         .     .     240'0 

At  between  1,500°  and  1,600°  F.,  ethylene  is  broken  up  into 
acetylene  aud  methane,  with  formation  of  benzene  ;  and  at  1,832° 
F.  napthalene  and  other  bodies  are  formed,  and  at  2,000°  F. 
are  again  broken  down  to  acetylene,  which  then  decomposes  into 
C  and  H.  (Professor  V.  B.  Lewes.) 

Not  more  than  2  cubic  feet  per  hour  of  ethylene  or  ethane  can  be 
used  in  a  "  London  "  Argand  burner  without  smoking. 

The  boiling  point  of  ethane  is  89-5  at  735  millimetres  pressure. 

The  density  of  liquid  ethane  was  found  to  be  0-446  at  0°  and 
0-396  at  +  10-5°.  (Dewar.) 

Illuminating  value  of  ethane  35,  ethylene  68,  acetylene  240. 

Propane  is  a  perfectly  colourless  liquid,  but  much  more  viscous 
than  liquid  carbon  dioxide. 

Heptane  was  found  practically  insoluble  in  water. 

Boiling  point  of  phenanthrene  equals  350°  C. 

Olefiant  gas  burns  well,  100  cubic  inches  weigh  30-57  grains. 
Density  is  -981. 

Acetylene  is  colourless  and  burns  with  a  very  brilliant  flame. 
Specific  gravity  is  -920.  If  chlorine  is  added  to  acetylene  the  mixture 
explodes. 

Specific  gravity  of  CS2  equals  1*29. 

CS2  boils  at  46°  C. 

CS2  vapour  ignites  at  300°  F.  (149°  C.)  when  ethylene  is  not 
present. 


Benzene  C6H6. 
Toluene  C7H8. 
Xylene  C8H10. 


Napthalene  C10H 
Heptane  C7H16. 


8- 


Propane  is  obtained  in  a  state  of  purity  by  heating  propyliodide 
with  aluminium  chloride  in  a  sealed  tube  to  130°.  After  subjection 
to  this  temperature  for  twenty  hours  the  tube  is  allowed  to  cool  and 
subsequently  placed  in  a  freezing  mixture.  (A.  E.  Tutton.) 

Lithium  hydride  is  formed  by  raising  metallic  lithium  to  a  red  heat 
in  an  atmosphere  of  hydrogen.  The  gas  is  absorbed  by  the  metal 
forming  a  white  powder  on  which  the  atmosphere  acts  only  very 
feebly.  When  wetted  the  powder  restores  the  hydrogen  it  has 
absorbed  and  the  quantity  given  off  is  greater  weight  for  weight  than 
is  obtainable  from  any  other  material. 

Argon  density  equals  19*940  to  19-941. 

Argon  viscosity  equals  121.     Air  equals  100. 

Specific  gravity  of  graphite  equals  2-15  to  2-35. 

G.E.  A  A 


354 


GAS   ENGINEER  S   POCKET-BOOK. 


Specific  gravity  of  hydrogen  gas  equals  '069. 

A  column  of  any  perfect  gas  expands  from  1  to  1*3665  between 
0°  C.  and  100°  G. 

One  cubic  foot  hydrogen  weighs  37  grains,  therefore  to  obtain 
weight  of  1  cubic  foot  in  gas  of  any  gas,  multiply  half  molecular 
weight  if  a  compound  gas,  or  molecular  weight  if  a  simple  gas  X  37. 

The  atomic  weight  of  an  elementary  gas  X  '0691  equals  its  specific 
gravity. 

Half  the  atomic  weight  of  a  compound  gas  or  vapour  X  '0691  equals 
its  specific  gravity. 

One  litre  H  gas  at  0°  C.,  and  760  millimetres  pressure,  weighs 
0*0896  grains. 

H  liquefies  at  about  -  200°  C. 

Specific  gravity  0  equals  1'1056,  liquefies  at  -14°  C.,  and  a  pressure 
of  320  atmospheres. 

To  obtain  weight  in  grains  of  any  gas  :  specific  gravity  X  537 
(weight  of  1  cubic  foot  air)  =  grains  per  cubic  foot. 

The  correct  temperature  of  the  boiling  point  of  propane  is  found  to 
be  -  37°  at  760  millimetres  pressure.  (Tutton.) 

Ammonia  density,  '589  ;  weight  of  100  cubic  inches  is  18'26  grains. 

The  hydrocarbons  in  unenriched  coal  gas,  which  give  it  its 
luminosity,  are  principally  methane,  ethylene,  and  benzene  vapour. 

Usually  accepted  theory  of  light  is,  that  there  are  three  distinct 
zones  ;  the  inner  zone  consisting  of  unburned  gas.  the  middle  lumin- 
ous zone,  where  the  H  changes  into  water,  developing  heat,  and 
consequent  incandescence  of  C,  and  the  outer  zone,  where  the  C 
becomes  carbon  anhydride. 


Flame  Temperatures.     (Professor  V.  B.  Lewes.) 

Inner  zone  temperature  rises  from  a  compar.itively  low  point  at  the 
mouth  of  the  burner,  to  between  1,000°  and  1,100°  at  the  apex  of  the 
zone.  Here  takes  place  the  conversion  of  the  hydrocarbons  into 
acetylene  :  the  luminous  zone,  in  which  the  temperature  ranges 
from  1,100°  to  a  little  over  1,300°,  with  a  decomposition  of  the 
elements  of  the  acetylene  formed  in  the  inner  zone  ;  the  extreme 
outer  zone,  in  which  the  cooling  and  diluting  influence  of  the  entering 
air  renders  a  thin  layer  non-luminous,  and  finally  extinguishes  it. 


•    Temperature  of  Different  Portions  of  Flame  in  Different  Oases. 

(Professor  V.  B.  Lewes.) 


Acetylene. 

Ethylene. 

Coal  Gas. 

Non-luminous  zone 
-  Commencement  of  luminosity  .     . 
Near  top  of  luminous  zone    . 

Degrees  C. 
459 
1,411 
1,517 

Degrees  C. 
952 
1,340 
1,865 

Degrees  C. 
1,023 
1,658 
2,116 

ILLUMINATING    VALUES    OF    HYDROCARBONS. 


355 


Temperature  of  the  mantle  of  a  coal  gas  flame  is  above  the  melting 
point  of  platinum.  (Smithells.) 

Hydrogen  and  CO  only  require  half  their  volume  of  0  for  complete 
combustion,  and  therefore  obtaining  this  quickly,  give  only  a  short 
flame.  Methane  requires  twice  its  volume  of  0,  and  thus  gives  a 
flame  nearly  four  times  as  long. 

A  flame  of  a  given  size  requires  a  volume  of  gas,  larger  or  smaller, 
according  to  the  illuminating  power  of  the  gas. 

The  cause  of  luminosity  in  coal  gas  flames  is  not  attributable  to  any 
one  hydrocarbon,  but  to  the  combined  action  of  all  that  are  present 
in  the  gas.  (Professor  Lewes.) 

The  illuminating  property  of  gas  depends  upon  the  presence  of 
about  4  per  cent,  of  unsaturated  hydrocarbons. 


Illuminating  Value  of  Hydrocarbons  per  5  Cubic  Feet  of  Vapour. 

(Professor  Lewes,  1890.) 


Methane  . 
Ethane 
Propane    . 
Ethylene 
Propene    . 


Candles. 
5-2 

.       35-7 

56-7 

.       70-0 

123-0 


Acetylene    , 
Benzene   . 
Toluene 
Napthalene 


Candles. 
.  240-0 
.  420-0 
.  741-7 
,  900-0 


The  illuminating  value  of  hydrocarbon  gas,  when  consumed  alone, 
may  be  approximately  calculated  from  the  heat  of  formation  or 
stored-up  potential  energy  of  the  elements  present  in  each  hydro- 
carbon. 


Methane 
Ethane       . 
Ethylene 
Acetylene  . 


Illuminating  Value. 


Calculated. 

8-4 

.  35-0 
.  60-9 
,  202-2 


Found. 

5-2 

35-0 

68-5 

240-0 

(Professor  Lewes.) 


Illuminat- 
ing Power, 
5  Cubic 

Oxygen 
required 
per  Cubic 
Foot  Con- 

Yield 
C02. 

Water 
Vapour. 

Quantity  Present  in 
Coal  Gas. 

sumed. 

Candles. 

Cubic 
Feet. 

Cubic 
Feet. 

Cubic 
Feet. 

Marsh  gas  . 

5-2 

2 

1 

2 

40  to  50  per  cent. 

Ethylene     . 

70 

3 

2 

2 

Benzene 

420*  820f 

H 

6 

8 

Acetylene    . 

400 

2 

2 

1 

Minute  quantity. 

Frankland.         f  Knublauk. 


A  A2 


356 


GAS  ENGINEER'S  POCKET-BOOK. 


Mr.  W.  Young  has  shown  that  where  feebly  luminous  gas,  which 
contains  a  large  surplus  of  potential  or  heat  energy,  is  carburetted, 
this  heat  energy  is  utilized  in  raising  the  potential  of  the  added 
hydrocarbons,  with  a  consequent  increase  of  light. 

Table  Showing  the  Comparative  Quantities  of  Various  Gases  of 
Different  Qualities  Required  to  Evaporate  an  Equal  Quantity 
of  Water.  (J.  Travcrs.) 

Cannel  gas 


Newcastle  coal  gas 


South  Wales 


.  of  24  candles 

.  „  22 

.  „  20 

.     .  „  16-5 

•  „  14-5 

,       „    •         •     •  „  13-5 

.  „  10-5 

and  20  %  cannel  „  14-0 


18-50  cubic  feet. 

19-75       „      „ 

20-50 

21-75 

22-00 

22-50 

28-00 

23-50 


The  Value  of  Coal  Gas  at  Different  Candle  Powers  for  Lighting 
and  Heating.     (D.  Wallace.) 


Candle  Power  of 
Gases. 

Comparative 
Specific  Gravity. 

Value  for  Heating. 

Value  for  Lighting. 

14-75 
26-24 
33-07 

1-000 
1-187 
1-298 

1-000 
1-295 
1-496 

i-ooo 

1-769 
2-230 

The  products  of  combustion  of  gas  are,  H20,  caused  by  the  com- 
bination of  the  hydrocarbons  of  the  gas  with  the  0  of  the  air,  and 
C02,  from  the  combination  of  the  C  with  the  O  of  the  air. 

The  proportion  of  sulphur  in  the  products  of  the  combustion  of 
coal  gas,  which  is  converted  directly  into  sulphurous  anhydride, 
ranges  from  89  to  99  per  cent. 

Cannel  enriched  London-  16-candle  coal  gas  gives  about  a  3-inch 
flame  in  a  "  London  "  Argand  burner. 

Carburetted  water  gas.  22-candle  power,  gives  only  about  a  2-inch 
flame,  owing  to  the  presence  of  less  methane.  (Professor  Lewes.) 

The  quantity  of  air  admitted  to  the  flame  is  principally  influenced 
by  the  pressure  at  which  the  gas  issues  from  the  orifice. 

5  cubic  feet  of  gas  at  ffihs  pressure  equals  11-14  candle  power. 

5  cubic  feet  of  same  at  ^ths  pressure  equals  20  candle  power, 
(Professor  W.  I.  Macadam.) 

Size  of  flame  from  carburetted  water  gas  is  less  than  with  coal  gas 
for  same  illuminating  power.  (Professor  Lewes.) 

Light  moves  with  a  velocity  of  about  180,000  miles  per  second. 

The  mechanical  equivalent  of  light  equals  749  foot  Ibs.  per  hour 
per  candle.  (Professor  Julius  Thomson.) 

Professor  F.  Clowes  finds  that  an  atmosphere  of  16-4  per  cent.  C. 
80-5  per  cent.  N,  and  3'1  per  cent.  C0a  will  extinguish  a  candle,  but 


TEMPERATURES   OP   FLAMES.  357 

can  support  a  coal  gas  flame  or  life,  whereas  an  atmosphere  that  will 
extinguish  a  coal  gas  flame  will  not  support  life. 

A  paraffin  flame  will  not  burn  in  less  than  16*6    per  cent.  O. 
A  candle  „  15'7      ,  0. 


A  methane  „  „  „  15'6 

AGO  „  „  „  13-35 

A  coal  gas  „  „  „  H'35 

AH  5-5 


O. 
0. 
0. 
0. 


(Professor  Clowes.) 

Temperature  of  a  Bunsen  Flame, 

Henry  W.  J.  Waggener  xound  that  the  highest  temperature  he 
could  get  was  1,704°  C.  or  3,100°  F.,  which  is  only  a  little  below 
the  melting  point  of  platinum  (1,780°  C.). 

The  Temperature  of  Bunsen  Flame.    (Professor  Warburg.) 

The  highest  temperature  found  was  1,704°  C. 

Strontium  flame  is  rose  coloured. 

Sodium  flame  is  blue  green. 

Mr.  Macpherson  showed  (1878)  that  there  was  a  proportionate 
relation  between  the  hydrocarbons  absorbed  by  bromine,  the 
durability  of  a  5-inch  flame,  and  the  illuminating  power  ;  and  that 
the  illuminating  power  and  the  durability  bore  a  fixed  relation  to  the 
percentage  of  C  in  the  gas. 

Durability  test  is  ascertaining  the  time  that  a  cubic  foot  of  gas 
will  make  a  flame  5  inches  high. 

With  the  durability  test,  and  a  jet  of  ^th  inch  diameter,  and 
5  inches  flame,  Dr.  Fyfe  found  that  the  quantity  consumed  was 
directly  as  the  square  root  of  the  pressure. 

In  setting  the  jet  photometer  to  work  it  should  be  calibrated  by 
means  of  a  Bunsen  photometer,  and  with  gases  of  different  qualities. 

The  water  line  in  a  jet  photometer  should  be  adjusted  at  least  once 
a  day  by  turning  off  the  gas  and  letting  out  all  pressure,  and  setting 
the  hand  at  zero  by  adding  more  water  as  required. 

8-8  inches 
— IQ —      Mercury  =  12  inches  water  pressure. 

One  cubic  inch  of  mercury  weighs  0-49  Ibs. 

Mercury  gauges  are  about  13£  to  14  times  shorter  than  water 
gauges. 

When  the  two  tubes  of  a  pressure  gauge  are  unequal  the  quantity 
of  liquid  displaced  in  each  tube  is  equal,  and  in  inverse  ratio  to 
their  sectional  areas. 

Different  sizes  of  tubes  in  U  pressure  gauges  have  no  effect  upon 
the  correct  registration  of  the  gauge,  the  absolute  difference  of  level 
being  the  same  for  a  given  pressure  despite  the  inequality  of  the 
glasses. 


358 


GAS  ENGINEER'S  POCKET-BOOK. 


Photometers,  &c. 

The  Board  of  Trade  Standards  Department  nas  settled  that  the 
cubical  contents  of  the  photometrical  room  is  not  to  be  less  than 
1,000  cubic  feet.  This  is  best  about  12  feet  long  by  9  feet  wide  by 
10  feet  high.  This  will  take  a  photometer  100  inches  or  60  inches 
long  between  the  gas  and  candles.  But  if  the  room  is  larger  it  will 
be  better  for  the  purpose — 1,500  or  2,000  feet  cubic  contents  are  not 
too  much. 

Such  ventilation  is  required  that  there  shall  be  an  ample  air 
supply  moving  at  a  low  velocity. 

Ventilation  of  the  photometer  room  is  a  very  important  point. 

The  air  removed  from  a  photometer  room  should  be  2,000  to  3,000 
cubic  feet  per  hour. 

Mr.  J.  Methven  found  that  air  at  increasing  temperatures, 
saturated  with  moisture,  decreased  the  light  emitted  from  a  flame 
rapidly  equals  10  per  cent,  between  50°  and  75°  F. 

The  area  which  the  light  covers  equals  1  at  1  foot,  but  at  2  feet 
equals  4,  at  3  equals  9,  and  at  4  equals  16. 


4=16 


I  FT. 


2  FT. 


3  FT, 


4  FT. 


With  the  shadow  photometer,  square  the  distances  of  the  two 
sources  of  light  from  the  screen,  and  divide  the  one  into  the  other. 

It  has  been  found  that  the  normal  eye  can  detect  a  difference  in 
strength  of  light  and  shadow  of  f§ths. 

With  a  Rumford  photometer  the  error  in  reading  need  not  be  more 
than  J^th,  and  should  not  in  usual  cases  be  more  than  1  per  cent. 

On  a  100-inch  photometer  bar  the  divisions  are  more  easily  read 
than  on  a  60-inch  one. 

60-inch  bar  in  photometer  is  preferable  to  100-inch  for  ordinary 
gases  from  14  to  30  candle  power,  owing  to  the  better  illumination 
of  the  disc. 

If  fog  is  present  the  60-inch  photometer  bar  is  best,  owing  to 
the  difference  in  value  between  the  gas  and  caudles  causing  the 


CALIBRATING   PHOTOMETER   BARS.  359 

greater  obstruction  on  the  one  side.  If  the  standard  should  be 
made  more  nearly  equal  this  advantage  of  the  60-inch  bar  would 
disappear. 

Formula  for  calculating  the  comparative  light  of  two  sources  : 
divide  the  distance  of  one  from  the  screen  by  the  distance  of  the 
other  and  square  the  quotient. 

To  Graduate  Photometer  Bar. 

100  */^"_l 
100  inches.  —  The  distance  from  the  candle  to  any  marks= 


where  a  =  the  number  to  be  placed  upon  the  mark. 

60  *T 


60  inches.— The  distance  from  the  candle  to  any  mark  = 


-  1 


To  Find  the  Distance  of  any  Mark  in  a  Photometer  Bar 
from  the  Standard. 


Distance  between  lights  X  (\/  number  of  candles  —  1) 
Number  of  candles  —  1 

=  distance  to  mark. 
To  prove  this  — 

distance  from  mark  to  light2 
distoce&ommark  to  standard* 


With  a  Fixed  Distance  for  the  Standard  from  Disc. 

\/  Number  of  candles  X  fixed  distance  =  distance  of  mark 

from  light. 

With  a  Fixed  Distance  for  the  Light  to  be  Tested  from 
the  Disc. 

fixed  distance 

-  =  distance  from  standard. 

\/Number  of  candles  required 

The  disc  should  be  examined  that  it  be  not  too  dry  or  too  old  or 
have  been  badly  made  ;  sometimes  the  two  sides  of  a  Bunsen  disc  will 
give  a  different  reading,  through  the  different  temperatures  to  which 
the  sides  are  subjected. 

The  Gas  Referees  for  London  insist  that  5  of  the  10  tests  shall  be 
made  with  the  one  side  of  the  disc  to  the  gas,  and  the  other  five  with 
the  opposite  side. 

After  making  5  of  the  10  tests  reverse  the  disc,  so  as  to  equalize 
any  difference  in  colour  of  the  two  sides  of  the  disc. 

If  the  disc  in  a  Bunsen  photometer  is  made  with  3  spots  fixed 
horizontally  and  the  disc  placed  slightly  obliquely,  the  per  cent,  of 
error  is  considerably  reduced  in  reading.  (Mr.  Heschus.) 


360  GAS  ENGINEER'S  POCKET-BOOK. 

A  chisel-shaped  crayon  has  been  used  instead  of  a  grease-spot  paper 
in  a  photometer.  The  crayon  is  cut  to  a  chisel  edge  and  fixed  with 
the  edge  in  a  vertical  position  ;  the  light  falling  upon  it  through  two 
slits  in  a  f-inch  tube  in  the  axis  of  which  the  crayon  is  fixed,  when 
the  lights  are  even  the  edge  disappears,  and  the  surface  appears  as 
aflat. 

A  photometer  has  been  made  in  which  the  decomposition  by  light 
of  ioduret  of  nitrogen,  prepared  by  the  action  of  a  pure  aqueous 
solution  of  ammonia  at  20°  upon  iodine,  and  noting  the  quantity  of 
nitrogen  produced  in  a  given  time,  and  the  distance  of  the  light 
from  the  liquid.  (L6on.) 

For  obtaining  the  illuminating  power  from  the  calorific  value  of 
a  coal  gas  Mr.  B.  H.  Thwaite  recommends  the  following  formula  : 

photometric  value  in  candles calorific  value  —  2280 

decimally  graduated  352-6 

the  Berthelot-Mahler  calorimeter  being  used. 

The  candle  balance  should  be  sufficiently  sensitive  to  weigh  ^th 
grain. 

Photometers  with  sliding  candles  are  not  now  stamped  by  the 
Standards  Department  of  the  Board  of  Trade. 

Standard  candles  should  be  8f  inches  from  base  to  shoulder  and 
are  made  of  spermaceti  with  from  4  to  5  per  cent,  beeswax. 

The  Gas  Referees  Instructions  allow  the  use  of  a  candle  burning 
within  5  per  cent,  of  the  prescribed  amount. 

The  chief  error  in  the  amount  of  light  emitted  by  a  candle  is  due 
to  variations  in  the  character  of  the  wick  employed. 

Variation  in  Light-giving  Power  due  to  Position  of  Wick. 
(J.  Methven.) 

Plane  of  curvature  of  both  wicks  parallel  to  plane  of  disc  equals 
1-999  candles. 

Plane  of  curvature  of  both  wicks  at  right  angles  to  plane  of  disc 
and  bent  away  from  disc  equals  1*957  candles. 

Plane  of  curvature  of  both  wicks  at  right  angles  to  plane  of  disc 
and  bent  towards  disc  equals  1-933  candles. 

The  cone  at  the  top  end  of  sperm  candles  should  not  be  used  in 
photometry,  but  a  good  cup  should  be  made  under  the  wick  by 
revolving  the  candle  in  the  hand  when  lighted,  allowing  the  grease 
to  fall  off,  the  extra  length  of  wick  should  be  removed.  They  should 
now  be  burnt  until  the  wicks  bend  over,  a  red  point  is  seen  showing 
through  the  flame,  which  should  be  of  its  maximum  size. 

No  candles  should  be  used  that  gutter  badly,  smoke,  or  form  badly 
shaped  "  cups  "  around  the  wick,  or  have  the  wicks  greatly  out  of  the 
centre,  or  too  closely  or  too  tightly  woven  wicks.  The  candles  should 
burn  at  least  10  minutes  before  commencing  to  test,  and  they  should 
be  placed  that  the  plane  of  the  wicks  are  at  right  angles  to  each 
other. 


PHOTOMETER  CANDLES.  361 

In  testing  gas  the  candles  having  been  made  in  a  mould  are  taper 
and  should  therefore  be  cut  in  half,  and  about  half  inch  of  the  wax  at 
the  middle  end  removed  from  around  the  wick  very  carefully  so  that 
the  latter  is  not  damaged.  All  candles  burning  more  than  126  grains 
or  less  than  114  grains  per  hour  should  be  rejected. 

The  spermaceti  employed  in  the  manufacture  of  standard  candles 
is  a  mixture  of  solid  fatty  ethers  and  a  small  quantity  of  oil,  with 
about  5  per  cent,  of  beeswax  to  prevent  crystallizing. 

Flames  of  Argand  gas  burners  vary  8|  per  cent,  in  a  range  of  22°  F. 
(J.  Methven.) 

A  comparison  between  different  candles  showed  a  maximum  varia- 
tion of  22'7  per  cent.,  and  in  one  case  the  average  of  10  experiments 
gave  a  difference  of  as  much  as  15  per  cent.  (Report  of  Committee 
on  Photometrical  Standards,  1881.) 

Candles  which  have  been  kept  about  8  years  show  a  reading  about 
8  per  cent,  higher  than  new  candles  will  do. 

Professor  Lewes  considers  the  candles  of  the  present  day  emit  less 
light  than  those  in  use  at  the  time  the  Act  was  passed  prescribing 
the  standard. 

At  50°  F.  the  light  from  120  grains  of  sperm  equals  T198  candles 
or  +  20  per  cent. 

At  72°  F.  the  light  from  120  grains  ol  sperm  equals  1'041  candles 
or  -f  4  per  cent. 

Flames  of  candles  vary  13  per  cent,  in  a  range  of  22°  F. 

The  gas  in  the  photometer  is  to  be  lighted  at  least  15  minutes 
before  the  testings  begin,  and  is  to  be  kept  continuously  burning 
from  the  beginning  to  the  end  of  the  tests.  The  candles  are  to  be 
lighted  at  least  10  minutes  before  beginning  each  testing,  so  as  to 
arrive  at  their  normal  rate  of  burning,  which  is  shown  when  the 
wick  is  slightly  bent  and  the  tip  glowing. 

To  correct  for  any  difference  in  the  rate  of  burning  of  the  candles— 

average  illuminating  power  x  600 
actual  time  taken  to  burn  120  grains. 


362 


GAS  ENGINEER'S  POCKET-BOOK. 


Time  taken  to  consume  10  grains. 

9'34"     9'39",   9' 45"     9'si"      9's?"     i°'s"     lo'g"     IO'J5" 
931        937       942      948       954         *°       106      1012     TO  i 


io's8" 
8"    io'25"     r 


41  40 

Grains  sperm  consumed 


39 
in  ten  minutes. 


CORRECTING   FOR   IRREGULAR   BURNING   OF   CANDLES.    363 

To  obtain  the  Correction  for  the  Irregular  Burning  of  the 
Candles  by  the  Diagram. 

Find  by  the  sloping  cross  lines,  the  actual  candle  power,  and 
immediately  above  the  figure  corresponding  to  the  number  of  grains 
burnt  in  10  minutes,  or  below  the  figure  corresponding  to  the  time 
taken  to  consume  40  grains,  proceed  horizontally,  and  note  the  figure 
above  "  40  ; "  this  will  give  the  candle-power  corrected  for  the  quantity 
of  grains  consumed. 

The  service  into  the  photometer  room  from  the  main  ought  to  be 
of  small  diameter,  and  also  be  of  lead  lined  with  tin  or  a  pure  tin 
pipe  laid  inside  an  iron  one  to  protect  it.  The  reason  for  this  is  that 
a  smooth  polished  surface  does  not  present  any  hold  for  napthalene 
to  attach  itself  to,  and  it  can  be  readily  washed  out  with  hot  water. 

A  very  important  matter  in  relation  to  the  supply  of  gas  to  a 
photometer  is  that  the  gas  should  come  direct  from  the  main  and  not 
through  any  meter  before  it  gets  to  the  photometer. 

An  Argand  burner  is  the  only  one  which  can  be  relied  upon  to 
maintain  a  steady,  vertical  light  in  a  photometer,  and  to  give  fair 
comparative  results  should  the  quality  of  the  gas  vary  a  candle  or  so 
up  and  down. 

Equal  areas  of  the  flames  of  gases,  with  illuminating  power  from 
12  to  60  candles,  have  equal  illuminating  powers. 

To  correct  for  any  difference  in  the  rate  of  burning  of  the  gas — 

average  illuminating  power  X  5 
actual  rate  of  burning. 


364 


GAS  ENGINEER'S  POCKET-BOOK. 


•*     rr>     N      w 


in 


tii 


i 


H 


EXPANSION   OF   GASES.  365 

Diagram  to  find  Corrected  Candle-power  of  Gas  according  to 
Quantity  burnt  per  hour. 

To  Use  the  Diagram. — Find  the  vertical  line  corresponding  to  the 
quantity  of  gas  consumed  in  ten  minutes,  and  the  sloping  curved  line 
corresponding  to  the  candle-power  corrected  from  the  point  where 
these  cross,  proceed  horizontally  to  the  centre  line,  when  the  figures 
thereon  will  show  the  actual  candle  power  corrected  for  the  quantity 
of  gas  consumed. 

Boyle's  or  Mariotte's  Law. 

The  volume  of  a  given  mass  of  any  gas  varies  inversely  as  the 
pressure,  thus — 

1  volume  gas  at  4  pressures  = 

2  ,,          ,     ,,2        „         = 

^  55  55          55       -*•  5? 

therefore  if  a  volume  of  gas  is  measured  at  any  barometrical  pressure 
the  volume  at  30  inches  is 

30  :  observed  pressure  :  :  volume  of  gas  :  required  volume. 

The  corrected  volume  of  gas  +  water  vapour  for  both  temperature 
and  pressure  equals 

observed  volume  X  (observed  pressure  -  tension  of  aqueous  vapour 

at  observed  temperature  X  17'64 

observed  temperature  +  460. 

Gas  expands  ^  of  its  own  volume  for  every  1°  C. 
„         „        5*3        „  „  „  1°  F.  (Charles's  Law.) 

therefore,  to  correct  any  volume  of  gas  measured  at  any  temperature 
(F.)  the  volume  at  60°  F.  equals 

(observed  temperature)  -  32  +  492)  :  (60°  -  32  +  492)  =  520  :: 

volume  :  required  volume. 


366 


GAS  ENGINEER'S  POCKET-BOOK. 


To  Use  the  Diagram. — Find  the  horizontal  line  corresponding  to 
the  barometrical  pressure,  and  the  vertical  line  corresponding  to  the 
temperature  of  the  room ;  at  the  point  where  these  two  lines  cross 
note  the  tabular  number  by  the  diagonal  curved  lines. 


Height  of  Barometer. 


990 
980 

970 
960 

95° 

940 
930 
920 

910 
900 
890 
880 
870 
860 


1030  I 

IO2O 
IOIO  o 

1000 

990 
8 

980  ' 

970 

960  g 
950 
940 

930  § 

920 

910 


Height  of  Barometer. 


TABULAR    NUMBERS. 
Height  of  Barometer. 


367 


1090 
1080 
1070 
1060 


»j 


990 

980 

970 
960 


3  5    Height  of  Barometer.     «j 

To  correct  for  temperature  and  barometrical  pressure, 
average  illuminating  power  X  1,000 

tabular  number. 

The  "  London  "  Argand  can  be  used  for  any  quality  of  gas  up  to 
18  candles  ;  and  from  18  up  to  25  candles  the  new  Preston  18-candle 
standard  "  London  "  Argand  may  be  used. 

The  new  proposal  of  the  Standards  of  Light  Committee  is,  that  the 
rate  of  consumption  of  the  gas  shall  be  set  to  give  a  light  equal  to 
16  candles,  and  the  candle-power  calculated  from  the  time  taken  to 
consume  £th  cubic  foot  (two  revolutions  of  the  test-meter  drum). 


368 


GAS    ENGINEERS    POCKET-BOOK. 


900 


95° 


Tabular  Numbers. 

looo  1050 


900 


950 


IOOO 

Tabular  Numbers. 


1050 


ii 

1 100 


HARCOURT'S  1 -CANDLE  PENTANE  UNIT.      369 


To  obtain  the  Correction  for  the  Tabular  Number  by  the  Diagram. 

Note  the  tabular  number,  proceed  up  the  line  immediately  above 
these  figures  until  it  cuts  the  sloping  line  corresponding  to  the  candle- 
power  found  by  the  photometer,  proceed  horizontally,  and  note  the 
figure  above  the  1,000  ;  this  will  be  the  actual  candle-power  of  the 
gas  at  60°  temperature  and  30-inch  barometrical  pressure. 

Mr.  Vernon  Harcourt's  1-Candle  Pentane  Unit. 

The  gas  used  for  this  standard  is  made  by  bringing  together  in  a 
gasholder,  air  and  the  highly  volatile  liquid  pentane,  in  the  pro' 
portion  of  one  cubic  foot  of  air  and  three  cubic  inches  of  pentane. 
The  pentane  to  be  used  is  a  mixture  of  pentane  with  some  paraffins 
of  lower  and  higher  boiling-points,  and  is  prepared  by  distilling  the 
light  petroleum  at  60°  C.,  at  55°  0.,  and  twice  at  50°  C.  The  pentane 
thus  prepared  must  satisfy  the  following  tests  :  On  agitation  with  ^th 
of  its  bulk  of  fuming  sulphuric  acid  for  five  minutes  it  must  impart 
to  the  acid  only  a  faint  brown  colour  ;  its  liquid  density  must  be 
between  -62  and  '63  at  62°  F.  ;  the  liquid  must  evaporate  absolutely 
without  residue  at  the  ordinary  temperature  when  the  tension  of  its 
vapour  is  not  less  than  7'5  inches  of  mercury;  the  density  of  the 
vapour  compared  with  air  must  not  be  less  than  2 '4  7,  nor  greater  than 
2-53. 

The  standard  1 -candle  pentane  unit  burner  consists  of  a  brass  tube 
4  inches  in  length  and  1  inch  in  diameter,  which  the  gas  enters 
towards  the  bottom.  The  upper  end  of  the  tube  is  closed  by  a  brass 
plug  \  inch  in  thickness,  in  the  middle  of  which  is  a  round  hole 
\  inch  in  diameter.  Around  the  burner  is  placed  a  glass  cylinder, 
6  inches  by  2  inches,  the  top  of  which  is  level  with  that  of  the 
burner,  air  entering  through  the  gallery  on  which  the  chimney 
stands.  Above  the  burner  is  supported,  at  a  height  of  63'5 
millimetres,  a  piece  of  platinum  wire  about  0'6  millimetres  in 
diameter,  and  from  2  to  3  inches  in  length.  The  air  gas  passes 
through  a  small  meter  delivering  at  each  revolution  ^th  of  a  cubic  foot, 
and  then  through  a  small  governor  fitted  to  regulate  the  flow  to  0'5 
cubic  foot  an  hour.  The  height  of  the  flame  is  adjusted  by  means  of 
a  delicate  stop-cock  until  the  top  of  the  flame  appears  to  touch,  but 
not  to  pass,  the  horizontal  platinum  wire  which  is  adjusted  so  as  to 
be  exactly  over  the  flame  and  to  extend  not  less  than  half  inch  beyond 
it. 

A  Sugg  16  candle  Standard  Burner  gives  only  about  0'6  per  cent, 
of  the  full  mechanical  equivalent,  while  a  Welsbach  incandescent 
burner  only  gives  1*4  per  cent.,  while  electricity  only  employs  about 
the  same  per  cent,  of  the  original  heat  energy  of  the  coal  used  for 
generating.  (Dr.  H.  Morton.) 

The  burner  used  for  Dibdin's  10-candle  pentane  standard  is  a 
modification  of  Sugg's  standard  "  London  "  Argand  burner. 

The  height  of  the  screen  in  the  10-candle  pentane  standard  should 
be  2-15  inches  above  the  steatite. 

G.E.  B  B 


370  GAS  ENGINEER'S  POCKET-BOOK. 

Herr  Von  Hefner-Alteneck's  Standard  of  Light. 

The  unit  of  light  should  be  a  free  burning  flame,  in  still  pure 
air,  supplied  by  a  section  of  solid  wick  and  fed  with  amyl-acetate ; 
the  wick-tube  to  be  circular  and  of  German  silver,  measuring  8 
millimetres  internal  diameter,  83  millimetres  external  diameter,  25 
millimetres  high. 

Flames  to  be  40  millimetres  high,  measured  from  the  edge  of  the 
wick-tube  at  least  10  minutes  after  lighting  the  lamp. 

A  variation  of  0'02  is  allowed  in  the  light  measurement. 

The  German  standard  candle  with  a  45  millimetre  flame  

Hefner  unit 

English  standard  candle 

Hefner  unit 

The  amyl-acetate  lamp,  devised  by  Herr  Hefner- Alteneck.  is 
practically  a  spirit  lamp  burning  the  vapour  of  amyl-acetate.  The 
wick  is  contained  in  a  round  tube  of  German  silver,  8  millimetres  in 
diameter  and  25  millimetres  high.  It  is  formed  of  a  strand  of  cotton 
yarns,  and  is  so  regulated  as  to  produce  a  flame  40  millimetres  in 
height.  It  is  supposed  to  give  a  light  equal  to  one  candle,  but 
Mr.  Dibdin  found  that  the  height  must  be  increased  to  51  milli- 
metres to  equal  the  light  of  one  candle  by  the  Methven  standard. 

The  Carcel  (French  photometrical  standard)  is  now  proved  to  be 
10  candles  (English  standard)  as  against  the  hitherto  variously 
estimated  9-2,  or  9'5,  or  9'8  candles.  (Journal  of  Gas  Lighting, 
July  llth,  1893.) 

Messrs.  Kirkham  and  Sugg  found  the  carcel  to  equal  9'6  candles. 

Table  Showing  the  Illuminating  Power  of  Different  Gases  after 
Carburetting  with  Gasolene  in  the  same  Carburettor. 

(J.  Methven.) 

Quality  of  Quality  of 

Gas  before  Gas  after 

Carburetting.  Carburetting. 

10-1     ....     73-98  average  of  2  tests. 
10-0        ....     71-18          „          2     „ 
16-0    .        .         .         .     70-05          .,          3     „ 
22-0        ....     67-77          .,          2     „ 
27-5     ....     70-09          „          2     „ 

It  will  be  noticed  that  the  resulting  quality  of  the  gas  is  about 
equal  in  each  case. 

Mr.  Vernon  Harcourt's  1-candle  pentane  unit  burner  consists  of  a 
brass  tube  4  inches  in  length  and  1  inch  in  diameter,  the  upper  end 
of  which  is  closed  by  a  brass  plug  J  inch  in  thickness,  in  the  middle 
of  .which  is  a  round  hole  £  inch  in  diameter.  A  glass  cylinder  6  inches 
long  x  2  inches  in  diameter  is  placed  with  the  top  level  with  that  of 
the  burner,  air  entering  at  the  bottom.  A  piece  of  platinum  wire, 


DIBDIN'S  IO-CANDLE  PENTANE  STANDARD.  371 

about  O6  millimetres  diameter,  is  fixed  at  63*5  millimetres  above  the 
burner.  The  air  gas  is  delivered  at  the  rate  of  about  half  a  cubic  foot 
per  hour,  and  the  flame  is  adjusted  so  that  the  tip  just  touches  the 
platinum  wire.  The  gas  is  a  mixture  of  1  cubic  foot  of  air  and  3  cubic 
inches  of  pentane.  The  pentane  used  is  mixed  with  a  distillation  of 
the  lighter  petroleums  at  60°  C.,  at  55°  C.,  and  twice  at  50° C.,  and  must 
pass  the  following  tests  :  It  must  be  of  '62  to  -63  liquid  density  at  62°  F., 
and  when  agitated  with  5  per  cent,  by  volume  of  fuming  sulphuric  acid 
for  5  minutes,  must  only  turn  the  acid  a  faint  brown  colour.  It  must 
entirely  evaporate  at  ordinary  temperatures  when  its  vapour  tension 
is  above  7-5  inches  of  mercury.  Its  vapour  density  must  be  between 
2-47  and  2-53.  In  regulating  the  height  of  the  flame  the  eye  should 
be  screened  from  the  luminous  portion  of  the  flame. 

As  long  as  the  bottom  of  the  carburettor  is  covered  by  the  pentane 
it  does  not  matter  what  depth  of  the  liquid  is  present. 

With  the  10-candle  standard  the  light  is  constant  between  42°  and 
73°  F. 

Pentane,  1  volume,  air  576  volumes,  measured  at  60°  F. ;  or  as 
gases,  20  volumes  of  air  to  7  of  pontane  gas. 

Pentane  is  a  product  of  the  distillation  of  petroleum  spirit,  having 
a  specific  gravity  of  '630  and  can  be  made  always  exactly  alike  ;  a 
certain  quantity  of  pentane  will  be  taken  up  by  atmospheric  air  if 
allowed  to  pass  over  its  surface. 

The  pentane  employed  to  produce  the  air  gas  used  in  Mr.  Harcourt's 
1-camlle  standard  and  in  the  carburettor  of  the  10-candle  pentane 
Argand  was  obtained  by  purifying  light  petroleum  by  the  successive 
action  of  sulphuric  acid  and  soda  solution,  and  then  distilling  at  60°  C., 
at  55°  C.,  and  twice  at  50°  C. 

Dibdin's  Pentane  Argand  Burner  Dimensions. 
Number  of  holes     ....        42 

Diameter       „ 0'028  inches  =     0-71  millimetres 

Inside  diameter  of  steatite     .        .  0-390      „      =     9-9          „ 

Outside        „  „  .     .  0-750      „      =    19-05 

Diameter  of  inside  of  metal  cone 

at  top 0-930      ,.      ==   23-62 

Chimney  length         ....  6-000      .,      =152-4 

Chimney,  inside  diameter      .        .  1-5         !,      =   33-1 

Height  of  cut-off        ....  2-15        ..      =   54-61         ., 

The  centre  of  the  flainc  should  be  immediately  over  the  terminal  of 
the  photometer  bar. 

Dibdin's  10-Candle  Pentane  Argand  Air  Gas  Standard. 

The  burner  is  a  specially  constructed  tri-current  Argand  burner, 
the  annular  steatite  ring  being  perforated  with  42  holes,  each  hole 
being  0'71  millimetre  in  diameter.  The  inner  perforated  cone  is 
punctured  with  ten  apertures  0-25  inch  in  diameter.  The  dimensions 
of  the  chimney  being  6  inches  high  and  1£  inches  inside,  the  top  of 
the  flame  should  be  maintained  as  nearly  as  possible  at  three  inches 

B  B  2 


372  GAS  ENGINEER'S  POCKET-BOOK. 

above  the  steatite.  The  middle  portion  of  the  screen  is  cut  away  so 
as  to  leave,  above  the  top  of  the  steatite  burner,  an  opening 
2*15  millimetres  in  height  and  1*4  inches  in  width,  the  lower  portion 
of  this  opening  being  exactly  level  with  the  top  of  the  steatite. 

The  carburettor  for  the  10-candle  pentane  Argand  consists  of  a 
circular  vessel  constructed  of  tinned  plate  203'2  millimetres  (8  inches) 
in  diameter  and  50'8  millimetres  (2  inches)  in  depth,  having  a  spiral 
division  25'4  millimetres  (1  inch)  in  width.  This  division  is  made  by 
soldering  in  a  spiral  strip  of  metal  4  feet  6  inches  in  length  and 

2  inches    wide,    gas-tight    to  the  under   side   of  the  top   of   the 
carburettor,  so  that  when  the  top  is  fixed  on,  the  bottom  of  the  strip 
comes  close  to  the  bottom  of  the  vessel  and  is  sealed  by  the  pentane, 
so  that  the  air  has  to  pass  over  pentane  for  a  distance  of  about 
4  feet  6  inches,  and  becomes  thoroughly  saturated.     At  the  end  of  the 
spiral  division,  near  the  side  of  the  carburettor,  a  bird  fountain  is 
fixed  for  charging  the  carburettor   and   keeping   it  charged  at  a 
constant  level  with  liquid   pentane.     The  lower  end  of  the  inlet 
fountain  is  closed,  and  rests  upon  the  bottom  of  the  tank.     Through 
the  side  of   the   tube,    which  is    0*4   inch    (10*1    millimetres)    in 
diameter,  16  holes,  1  millimetre  in  diameter,  are  bored,  close  to  the 
bottom,  and  through  these  the  pentane  enters  the  carburettor.     At 
one  side  of  the  inlet-tube,  1  inch  from  the  lower  end,  a  small  tube 

3  millimetres  in  diameter  and  20  millimetres  in  length  is  connected 
thereto  and  turned  upwards.     The  fountain  inlet-tube  is  carried  up 
through  the  top  of  the  carburettor,  and  continued  in  the  form  of  a 
bulb  having  a  capacity  of  about  200  cubic  centimetres. 

When  the  carburettor  is  being  charged  the  gas  must  be  ex- 
tinguished, to  avoid  the  risk  of  the  vapour  firing  and  causing  an 
explosion. 

To  Test  Lime  for  its  Purifying  Value. — Take  a  small  quantity  of 
lime,  weigh  and  add  sufficient  water  to  slake ;  dry  and  re-weigh, 
when  increased  weight  shows  quantity  of  water  required  to  convert 
the  caustic  to  hydrate  ;  then,  as  56  parts  caustic  lime  will  absorb  18 
parts  water,  the  percentage  of  the  former  can  easily  be  ascertained. 

To  test  if  lime  has  been  thoroughly  burnt,  add  dilute  hydrochloric 
acid,  when  no  great  effervescence  should  be  given  off. 

To  Find  the  Quantity  of  C02  or  H2S  that  a  Sample  of  Lime  will 
absorb— 

per  cent,  pure  lime 

5  X    -         — Tnf\ =  number  of    cubic  feet  of  COa 

or  H2S  absorbable. 

1  Ib.  pure  Fe208  will  unite  with  0*603  Ib.  or  6'7  cubic  feet  H2S. 
Water  will  take  up  ^th  of  its  weight  of  lime,  and  is  then  saturated. 
When  limestone  is  burnt  the  C02  is  expelled  as  per  equation — 

CaC08  =  CaO  +  C02. 

One  part  pure  CaOH2O  will  unite  with  -594  parts  C02  or  -460  H2S 
or  1-lb.  pure  lime  will  unite  with  5  cubic  feet  of  either  CO,  or  H2S. 

To  Test  Caustic  Lime. — Take  a  sample  of  known  weight  and 
thoroughly  slake  it,  dry  in  an  air  bath  at  250°  F.,  and  weigh ;  the 


TO   TEST   OXIDE    OF    IRON.  373 

increase  of  weight  will  indicate  the  quantity  of  water  taken  up  in 
rendering  the  caustic  lime  into  hydrate.  Nine  parts  of  water  will  be 
absorbed  for  every  28*5  grains  caustic  lime,  then 

28-5  x  difference  in  weight 

g —  —  =  quantity  of  caustic  lime. 

If,  however,  any  of  the  lime  has  absorbed  moisture  from  the  air,  this 
will  not  show  it. 

Hydrated  peroxide  of  iron  equals  Fe20s,  3  H20,  which  unites  with 
3  H2S  to  form  2  FeS  +  fi  H20  +  S,  and  on  revivification  2  FeS  + 
3  H2O  +  30  equals  Fe203,  3  H2O  +  2S.  Sulphate  of  iron  equals  FeO, 
S03,  which  unites  with  H2S  and  NH3  to  form  FeS  +  NH40,  S03. 

Lime  equals  CaO,  which  unites  with  the  equivalent  of  H20  to  form 
CaOH20,  equals  hydrate  of  lime,  which  combines  with  C02  to  form 
CaOC02  +  H?0,  or  with  H2S  to  form  CaS  +  2H20. 

When  lime  which  has  taken  up  H2S  and  become  CaS  +  H20  is 
presented  to  C02  it  becomes  CaOC02  -f-  H2S,  the  H2S  being  driven  off, 
owing  to  the  greater  affinity  of  CaO  for  C02. 

Sulphide  of  lime  (CaS)  combines  with  CS2  to  form  CaS,  CS2  equals 
sulphocarbonate  of  lime,  which  requires  a  longer  contact  for 
combination  than  is  necessary  with  H2S  or  C02. 

Hydrochloric  acid  will  dissolve  hydrated  ferric  oxide,  but  has  little 
effect  on  anhydrous  ferric  oxide. 

To  Test  Spent  Oxide  of  Iron,  Lime,  or  Weldon  Mud  for  Sulphur. — 
Dry  the  sample  at  212°  F.  until  a  constant  weight  is  obtained,  then 
place  in  a  test  tube  with  a  little  cotton  wool  at  the  bottom,  pass  a 
quantity  of  CS2  (about  three  or  four  times  the  bulk  of  the  oxide) 
through  it,  and  allow  the  solution  to  fall  into  a  flask,  evaporate  the 
CS2  with  heat,  when  the  S  will  remain  in  the  flask  and  the  quantity 
can  be  easily  found. 

Mr.  A.  J.  Bale  proposed  to  so  arrange  the  apparatus  for  testing 
spent  oxide  for  sulphur  that  the  bisulphide  of  carbon  is  evaporated 
and  condensed,  and  then  to  pass  through  the  oxide  to  the  evaporating 
flask  to  again  go  through  the  cycle  until  all  the  sulphur  has  been 
removed  from  the  oxide,  and  by  this  means  reduce  the  quantity  of 
bisulphide  necessary. 

When  testing  oxide  by  the  bisulphide  method,  care  should  be  taken 
that  the  oxide  has  been  thoroughly  revivified. 

Place  dilute  hydrochloric  acid  in  a  wide-mouthed  bottle  and  stand 
in  this  a  small  vessel  containing  the  spent  oxide,  connect  to  measuring 
tube  immersed  in  water,  overturn  the  oxide  into  the  acid,  when  the 
quantity  of  H2S  driven  off  will  be  found  by  the  displacement  of  the 
water  in  the  measuring  tube.  Twenty-five  grammes  spent  oxide  is 
the  best  amount,  and,  when  fresh  from  the  purifier,  will  evolve  about 
250  cubic  centimetres  of  H2S. 

Four  days  will  usually  suffice  to  revivify  oxide. 

Temperature  of  oxide  while  revivifying,  and  in  presence  of  ample 
moisture,  may  reach  140°  to  160°  F. 

One  ton  of  good  oxide  should  purify  1£  to  1£  millions  cubic  feet 
before  becoming  spent. 


374 


GAS  ENGINEER'S  POCKET-BOOK. 


Volumes. 
78,000 
3,300 
253 
100 

Volumes. 
Oxygen       ....     3-7 
CO         1-56 
N        1-56 
H  1-50 

12'5 

Light  carburetted  hydrogen    1  -(50 
(Dr.  Frankland.) 

Beckton  Purifying  Method. 

2  carbonate  vessels  for  the  elimination  of  C02 
2  oxide  „  „  H2S 

2  sulphide          „          „  „  CS2  etc. 

2  weldon  mud   „  „  „  H2S     driven     off    from 

sulphide  vessels. 

100  Volumes  Water  at  60°  F.  and  30  Inches  Barometer  will 
absorb — 


Ammonia     . 
Sulphurous  acid 
H2S      . 
C02 
Olefiant  gas 


One  volume  H20  at  0°  C.  dissolves  4-37  volumes  H2S. 
H2S  unites  with  an  equal  weight  of  NH3. 
22  parts  C02  unite  with  17  parts  NH8. 

Quantities  of  Gases  Absorbed  by  Water  at  20°  C.  at  760  Millimetres 

Pressure. 

Hydrogen    .         .  1-9  per  cent,  of  the  volume  of  water. 

N    .        .        .     .  1-4 

O  2-9 

Methane          .     .  3-5 

GO      .  2-3 

C02  .  .  .  90-0 
Ethylene  .  .  15-0 

Acetylene  .  .  95'0 
H2S'  .  .  .  291-0 
NH8  .  .  .  74,000-0 

To  Find  the  Amount  of  C0.2  in  Gas  Liquor. 

Add  an  excess  of  barium  chloride  to  a  known  quantity  of  gas 
liquor,  digest  for  30  minutes  at  a  gentle  heat,  filter,  then  dry,  ignite, 
and  weigh  the  precipitate.  Every  98'5  parts  of  barium  carbonate 
contains  22  parts  C02. 

To  Estimat:  the  Quantity  of  Free  Ammonia  in  Liquor. 

Take  a  glass  measure  graduated  into  16  parts,  fill  with  liquor  and 
empty  into  a  glass  beaker,  rinse  the  measure  with  distilled  water  and 
add  rinsings  to  liquor  in  beaker  with  a  few  drops  of  methyl  orange 
indicator.  Kinse  the  measure  with  a  little  10  per  cent,  acid  solution 
and  throw  away  rinsings,  fill  up  measure  with  10  per  cent,  acid  solu- 
tion (specific  gravity,  1,064-4  at  60°  F.),  and  pour  acid  very  gradually 
into  beaker  until  the  liquor  is  neutralized.  The  number  of  divisions 
of  acid  solution  used  equals  ounces  strength  of  liquor. 

To  Estimate  the  Quantity  of  Ammonia  in  Liquor. 
Mix  a  known  quantity  of  the  liquor  with  an  excess  of  caustic  lime 
or  soda,  heat,  and  lead  the  evolved  fumes  of  ammonia  through  a  solu- 


10    PER   CENT.    ACID    SOLUTION. 


375 


tion  of  sulphuric  acid  (10  per  cent.)  until  all  the  gases  of  ammonia 
are  evolved,  titrate  the  acid  solution,  with  10  per  cent,  alkaline  solu- 
tion, note  quantity  of  latter  necessary  to  neutralize,  deduct  from 
quantity  of  acid  solution  used,  equals  strength  of  ammonia  in  liquor. 

Ounces  strength  of  ammoniacal  liquor  is  the  number  of  ounces  by 
weight  of  H2S04  (specific  gravity  1,064-40  at  60°)  required  to  neutra- 
lize a  gallon  of  the  liquor. 

To  convert  degrees  Twaddell  to  specific  gravity  (water  equals  1 ) — 
(Degrees  x  '005)  +  1. 

To  convert  specific  gravity  into  degrees  Twaddell — 
Deduct  1  and  divide  by  -005. 

Every  ounce  strength  of  ammoniacal  liquor  equals  '347  ounces  of 
absolute  ammonia. 

Specific  Gravity  of  10  per  cent.  Acid  Solution  at  Various 
Temperatures.     (L.  T.  Wright.) 


Temperature. 

Specific 
Gravity. 

Temperature. 

Specific 
Gravity. 

Temperature. 

Specific 
Gravity. 

F. 

c. 

F. 

C. 

F. 

C. 

40 

4-45 

1068-10 

54 

12-23 

1065-64 

68 

20-00 

1062-72 

41 

5-00 

1067-94 

55 

12-78 

1065-45 

69 

20-56 

1062-51 

42 

5-56 

1067-78 

56 

13-34 

1065-24 

70 

21-11 

1062-30 

43 

6-11 

1067-62 

57 

13-90 

1065-03 

71 

21-67 

1062-08 

44 

6-67 

1067-46 

58 

14-45 

1064-82 

72 

22-23 

1061-86 

45 

7-23 

1067-30 

59 

15-00 

1064-61 

73 

22-78 

1061-64 

46 

7-78 

1067-12 

60 

15-56 

1064-40 

74 

23-34 

1061-42 

47 

8-34 

1066-94 

61 

16-11 

1064-19 

75 

23-90 

1061-20 

48 

8-89 

1066-76 

62 

16-67 

1063-98 

76 

24-45 

1060-97 

49 

9-45 

1066-58 

63 

17-23 

1063-77 

77 

25-00 

1060-74 

50 

10-00 

1066-40 

64 

17-78 

1063-56 

78 

25-56 

1060-51 

51 

10-56 

1066-21 

65 

18-34 

1063-35 

79 

26-12 

1060-28 

52 

11-11 

1066-02 

66 

18-89 

1063-14 

80 

26-67 

1060-05 

58 

11-67 

1065-83 

67 

19-45 

1062-93 

85 

29-45 

1058-95 

Test  for  Sulphuretted  Hydrogen. 

The  gas  is  dried  and  passed  through  U  tubes  containing  cupric 
phosphate  on  one  side  and  non-alkaline  calcium  chloride  on  the 
other,  the  difference  in  weight  of  the  U  tube  giving  the  quantity  of 
sulphuretted  hydrogen  in  the  amount  of  gas  passed.  (L.  T.  Wright.) 

Another  Test  for  Sulphuretted  Hydrogen. 

The  gas  is  made  to  bubble  through  an  acid  solution  of  cadmium 
chloride  in  two  or  three  Woulffe's  bottles,  when  cadmium  sulphide 
is  precipitated,  which  may  be  washed,  filtered  and  weighed,  and  the 
quantity  of  H2S  thus  obtained. 

Sheard's  Test  for  Ammonia,  H2S  and  C02  in  Gas. 
Four  absorption  tubes  are  required  and  a  filter  tube  containing 
cotton  wool  to  absorb  tarry  matters  when  testing  crude  gas.     In  the 


376  GAS  ENGINEER'S  POCKET-BOOK. 

first  tube  a  certain  quantity  of  half  deci-normal  strength  sulphuric 
acid  is  placed;  in  the  second  a  quantity  of  cupric  sulphate  1  part 
and  water  10  parts  (30  cubic  centimetres  of  this  should  absorb  all  the 
H2S  from  500  cubic  centimetres  crude  gas)  ;  in  the  third  and  fourth 
tubes,  say,  30  cubic  centimetres  and  20  cubic  centimetres  of  barium 
hydrate.  The  first  tube  is  the  test  for  NH3,  the  second  for  H0S, 
and  the  other  two  for  C02.  Pass,  say,  500  cubic  centimetres  of  sjas 
slowly  through  the  apparatus,  and  then  1 ,000  cubic  centimetres  of  air  to 
ensure  that  the  whole  of  the  gas  has  passed  over  the  whole  of  the 
apparatus.  Wash  out  the  glass  scrubber  of  each  absorption  tube 
with  a  little  distilled  water.  Titrate  the  contents  of  the  first  tube 

with   -^Q  ammonia    HO,  using  cochineal   as  an  indicator,  note  the 

quantity  required  to  neutralize,  and  deduct  this  from  the  quantity  of 
sulphuric  acid  placed  in  the  tube  X  74  =  grains  of  ammonia  per 
100  cubic  feet  gas.  Titrate  the  second  tube  with  similar  ammonia 
solution,  and  use  methyl  orange  as  indicator  X  74  =  grains  H2S  per 

100  cubic  feet  gas.  (Each  cubic  centimetre  ^  acid  =  74  grains  NH3 
per  100  cubic  feet  of  gas.  Each  cubic  centimetre  —  ammonia  re- 
quired to  neutralize  =  74  grains  H2S  per  100  cubic  feet  gas.)  Titrate 
the  washings  of  the  third  and  fourth  tubes  with  — HC1,  deduct  the 

quantity  required  to  neutralize  from  equivalent  of  —  Ba  HO,  first 
put  in  tube  X  0'24  =  volumes  per  cent,  of  C0a. 

Harcourt's  Colour  Test  for  H2S. 

Here  the  gas  is  passed  straight  through  the  acetate  of  lead  solution 
until  the  correct  colour  is  obtained,  when  the  quantity  of  gas  passed 
contains  0-0025  grains  S,  and  as  S  exists  in  H2S  in  the  proportion  of 
32  to  2  H  by  weight,  the  quantity  of  H2S  can'be  readily  found. 

Harcourt's  Colour  Test  for  CS2. 

The  gas  containing  CS2  is  made  to  pass  over  heated  platinised 
pumice,  when  the  equivalent  amount  of  H2S  is  formed  and  made  to 
bubble  through  a  solution  of  acetate  of  lead  until  the  latter  is  turned 
to  a  brown  shade  of  a  certain  tint,  when  the  quantity  of  gas  passed 
over  the  pumice  is  noted,  and  to  effect  this  an  amount  of  H2S  equal  to 
0*0025  grains  S  must  have  been  in  the  gas,  from  which  the  quantity 
per  100  cubic  feet  may  be  ascertained.  7  or  8  grains  per  100  cubic 
feet  should  be  added  to  the  quantity  found  by  above  test  for  other 
sulphur  compounds  not  acted  upon  by  above  method. 

If  the  gas  is  not  already  freed  from  HaS  it  must  be  passed 
through  an  oxide  purifier  before  being  allowed  to  grt  to  the 
pumice. 

A  diagram  to  facilitate  the  calculation  of  S  from   the   divisions 
of  the  measuring  cylinder  commonly  used,  which  latter  equal 
cubic  feet  is  shown. 


HARCOURT'S  COLOUR  TEST. 


Diagram  for  use  with  Harcourt's  Colour  Test. 


500 


Grains  of  Sulphur  =  Divisioris  of  Measuring  Cylinder. 


140 


130 


378  GAS  ENGINEER'S  POCKET-BOOK. 

To  Test  for  Presence  of  Acetylene. 

Bring  the  gas  into  contact  with  ammoniacal  cuprous  chloride 
solution  when  red  acetylide  of  copper  is  formed  ;  aspirate  the  gas  into 
a  flask  containing  the  blue  cuprous  chloride,  agitate,  and,  if  acetylene 
is  present,  the  sides  are  at  once  coated  with  the  red  compound. 


The  gas  is  bubbled  through  a  small  orifice  under  lime  water,  made 
by  mixing  slaked  lime  and  water  and  decanting  the  clear  liquid  when 
time  has  been  allowed  for  the  mixture  to  settle.  If  C0a  is  present  in 
the  gas  the  lime  water  becomes  milky. 


Charge  two  absorption  tubes  with  20  or  30  cubic  centimetres  each 
deci-normal  barium  hydrate  solution  ;  pass  500  cubic  centimetres  of 
gas  through,  then  immediately  500  cubic  centimetres  air.  Wash  out 
the  absorption  tubes,  add  a  few  drops  phenol-phthalein  and  titrate 
with  deci-normal  hydrochloric  acid.  Deduct  quantity  of  acid  re- 
quired to  neutralize  from  equivalent  of  barium  hydrate  used  equals 
amount  of  C02  absorbed  from  500  cubic  centimetres  of  gas  — 

X  0-241  =  per  cent,  by  volume 
X  1'92    =  grains  per  cubic  foot 

0-0022  gramme  C02  is  equivalent  to  1  cubic  centimetre  of  deci- 
normal  acid. 

0'914  gramme  equals  weight  of  500  cubic  centimetres  of  C0a 
saturated  with  moisture. 

28,315  cubic  centimetres  equals  value  of  1  cubic  foot. 

15,432  grns.  equals  value  of  1  gramme. 

To  Detect  Oxygen  or  Air  in  Coal  Gas.  —  Fill  a  graduated  glass  with  gas 
and  then  bring  in  contact  with  a  solution  of  pyrogallic  acid,  made 
alkaline  with  caustic  potash  ;  when  oxygen  is  absorbed,  the  rise 
of  the  acid  in  the  graduated  tube  showing  the  quantity  of  oxygen 
absorbed  from  the  gas,  this  quantity  X  5  equals  quantity  of  air. 

The  quantity  of  oxygen  is  usually  obtained  by  subtracting  the 
weight  of  all  the  other  constituents  from  the  original  weight  of  the 
substance  being  analysed. 

To  Convert  Percentage  of  C00  and  H.,S  into  Cubic  Inches  per 
Gallon. 

™.  for  Ha 


Methods  of  obtaining  Specific  Gravity  of  Gases. 

Direct  Method.  —  Weigh  a  hollow  vessel,  in  an  exhausted  state, 
then  filled  with  air,  and  afterwards,  when  filled  with  the  gas  under 
test,  weight  of  air  ^  weight  of  gas  equals  specific  gravity. 


SPECIFIC   GRAVITY   OF    GASES.  379 

Aerostatic  Method. — A  balloon  of.  say,  1  cubic  foot  capacity  is 
filled  with  the  gas  and  the  balloon  weighted  until  it  is  just  prevented 
rising  in  the  air.  Weight  of  air  displaced  by  balloon  -  weight  of 
balloon  when  weighted  equals  weight  of  gas ;  then  weight  of  air  dis- 
placed ~  weight  of  gas  equals  specific  gravity. 

Effusion  Method. — If  any  gases  are  expelled  at  same  pressure 
through  a  small  aperture  in  walls  of  minute  thickness  the  squares  of 
the  velocity  of  expulsion  are  in  inverse  ratio  to  the  specific  gravity  of 
the  gases. 

Liquid  Balance  Method. — If  the  lower  end  of  a  tube  of  some 
length  be  immersed  in  liquid  the  height  of  the  liquid  in  the  tube  will 
vary  according  to  the  specific  gravity  of  the  "gas  in  the  tube. 

Hydrometer  Method. — Place  a  hydrometer,  with  a  hollow  glass 
ball,  hermetically  sealed  at  top,  into  a  glass  cylinder  partly  filled 
with  water,  and  cover  all  with  a  further  glass  bell  and  pass  gas 
through  the  latter  so  that  hydrometer  ball  is  surrounded  by  the  gas, 
when  the  hydrometer  will  rise  and  fall  according  to  the  specific 
gravity  of  the  gas. 

Lux's  Gas  Balance  Method. — Pass  air  through  the  globe  and  note 
the  position  of  pointer,  and  move  scale  to  equal  I'OO,  then  pass  gas 
through  and  note  the  position  of  pointer,  and  the  figure  against 
same  at  pointer  equals  specific  gravity  of  gas.  The  sensitiveness  of  the 
apparatus  can  be  increased  by,  or  diminished  by,  raising  or  lowering 
the  centre  of  gravity  of  the  balance  from  the  centre  of  motion. 


To  Determine  the  Specific  Gravity  of  a  Gas.    (Greville  Williams.) 

Pass  air  through  one  bottle  potassium  hydrate  solution,  two  bottles 
sulphuric  acid,  6  U-tubes  of  very  active  soda-lime,  and  4  U-tubes  of 
calcic  chloride,  and  then  through  a  glass  globe  with  stop-cock  at  each 
side,  and  after  passing  through  the  globe  through  one  more  tube  of 
calcic  chloride.  The  air  should  be  drawn  through  by  an  aspirator 
until  the  weight  becomes  constant  and  temperature  regular.  Shut 
tap  of  globe  on  aspirator  side  and  remove  rubber  connection  on  that 
side  and  then  close  the  other  tap.  Wipe  the  globe  with  a  silk  hand- 
kerchief and  hang  by  platinum  wire  to  one  side  of  a  balance. 
Counterpoise  with  globe  of  a  little  smaller  capacity,  using  weights  to 
exactly  balance.  Note  these  weights  required  and  call  weight  of 
balloon  and  air. 

Pass  the  gas  to  be  tested  slowly  through  6  U-tubes  of  soda-lime  to 
remove  all  trace  of  C02,  and  through  4  tubes  of  calcic  chloride  for  one 
hour,  then  through  the  globe  with  a  further  tube  of  calcic  chloride 
on  outlet.  Shut  off  the  inlet  tap  and  then  immediately  the  outer  tap. 
Fix  and  weigh  as  before  equal  to  weight  of  balloon  and  gas. 

Specific  gravity  of  the  gas  equals  capacity  of  balloon  or  globe  in 
cubic  centimetres  multiplied  by  weight  of  1  cubic  centimetre  air  at 
the  temperature  in  °C.  of  the  test,  less  the  difference  in  weight  of  the 
balloon  divided  by  the  capacity  of  the  balloon  multiplied  by  weight 
of  1  cubic  centimetre  air, 


380  GAS  ENGINEER'S  POCKET-BOOK. 

To  Obtain  the  Specific  Gravity  of  any  Coal. 
Weigh  a  small  piece  in  and  out  of  distilled  water  (02°  F.)  then 

Weight  in  air _g       .fi 

'  loss  of  weight  when  weighed  in  water 

Specific  gravity  of  any  substance  X  1,000  equals  weight  in  ounces 
(avoirdupois)  per  cubic  foot. 

To  Obtain  Value  of  Gas  in  Grains  Sperm  per  Cubic  Foot. 
Illuminating  power  X  120 


To  Obtain  Value  of  Coal  per  Ton  in  Ibs.  Sperm. 

Value  in  grains  sperm  per  cubic  foot  x  cubic  feet  made  per  ton 

7,000 
or, 

Cubic  feet  made  per  ton 

— g —  -  X  illuminating  power  X  3 

175 

Average  Analysis  of  Bituminous  Coal. 

Caking.  Non-caking. 

Specific  gravity    .         .         .  1-267  1-279 

C 80-05  77-19 

H 5-92  5-2G 

O      .         .   '     .         .         .     .  8-98  12-01 

N 2-21  1-89 

S 1-13  -64 

Ash 1-72  3-02 

Determination  of  the  Caking  of  Coal.     (Louis  Campredon.) 

The  coal  is  powdered  to  pass  through  a  sieve  of  2.580  meshes  per 
square  inch,  and  a  fixed  quantity — say  1  gramme — of  it  is  mixed  with 
various  amounts  of  uniformly  fine  sand.  Each  sample  of  coal  and 
sand  is  heated  to  redness  in  a  small  porcelain  crucible,  and  the 
character  of  the  residue  is  observed  when  cool.  From  the  various 
samples,  the  maximum  quantity  of  sand  which  may  be  added  to 
the  given  weight  of  coal  with  the  production  of  a  firm  cake  on 
heating  is  found.  The  weight  of  coal  is  t:;ken  as  unity  in  the  scale 
of  comparison  ;  and  the  caking  power  of  coal  which  leaves  a  powdery 
residue  is  of  course  nil.  The  highest  result  found  with  any  coal  was 
17°  on  this  scale  ;  pitch  gave  20°. 

The  illuminating  power  of  140  samples  of  caking  coal  varied  from 
12-5  to  18-5  candles,  and  the  quantity  purified  by  1  cwt.  lime  varied 
from  10,000  to  18,000  cubic  feet. 


TESTS    OF    COAL. 


381 


Table  Showing  the  Changes  Wood  Undergoes  in  Becoming  Coal. 

(Roscoe  and  Schovlcmmer.) 


C. 

H. 

O  and  N. 

Wood      

50-00 

6-00 

44-00 

Irish  peat  

60-02 

5-88 

34-10 

Lignite  from  Cologne 

66-96 

5-25 

27-76 

Earthy  coal  from  Da,x        .     . 

74-20 

5-89 

19-90 

Canncl  coal  from  Wigan. 

85-81 

5-85 

8-34 

Newcastle  Hartley     .         .     . 

88-42 

5-61 

5-97 

Welsh  anthracite    . 

94-05 

3-38 

2-57 

Graphite    

100-00 

o-oo 

o-oo 

Average  Analysis  of  Welsh  Anthracite.     (J.  Hornby.) 

Per  Cent. 

Fixed  carbon 89'84 

Ash 1-20 

Sulphur 0-80 

Moisture 2'25 

Volatile  matter 6'01 

Lignite  specific  g'ravity  equals  1*15  to  1'3. 
Bituminous  coal,  specific  gravity  equals  1-25. 

Tests  of  Coal. 

Dry  coal  at  100°  C.,  weigh  every  2  hours,  and  note  lowest  weight  to 
obtain  amount  of  moisture. 

To  obtain  quantity  of  coke  or  volatile  matter,  weigh  coal  in  platinum 
crucible,  burn  off  over  powerful  Bunsen  flame  until  all  gas  is  driven 
off,  allow  to  cool  in  dessicator  and  weigh  ;  residue  =  coke.  Original 
weight  -  coke  =  gases. 

To  estimate  quantity  of  asb,  weigh  coal  in  a  platinum  boat  and 
heat  it  in  a  glass  tube  to  red  heat,  air  being  slowly  drawn  through 
the  glass  tube  ;  cool  and  weigh  boat. 

To  find  total  quantity  of  sulphur,  weigh  coal  with  four  times  its 
weight  of  sodium  and  potassium  carbonates  mixed  in  molecular  pro- 
portions in  platinum  crucible.  Heat  over  Argand  spirit  lamp,  and 
slowly  increase  to  just  below  visible  redness  until  coal  becomes  faintly 
grey,  then  raise  heat  to  a  faint  red  for  40  to  60  minutes  ;  cool. 


Products  of  Distillation  of  1  Ton  Newcastle  Coal. 

Temperature  of  Distillation, 

1,000°  to  1,200°  F. 

Gas       .         .     7,450   cubic  feet. 
Tar  ...          18J  gallons. 
Coke     .  1,200    Ibs. 


(Gesner.) 


Products  of  the  Tar. 
Benzol       .  .     3  pints. 

Coal  tar  naphtha  .     .     3  gallons. 
Heavy  oil  and  naph- 
thalene .        .        .9        . 


Temperature  of  Distillation, 

750°  to  800°  F. 

Gas         .        .     1,400  cubic  feet 
Crude  oil    .     .          68  gallons. 
Coke       .         .     1,280  Ibs. 


Products  of  the  Crude  Oil. 
Eupion   .         .        .2    gallons. 
Lamp  oil    .         .     .  22  £       „ 
Heavy      oil       and 

paraffin        .        .  24         ., 


382 


GAS    ENGINEERS    POCKET-BOOK. 


Composition  of  Fuels  (Ash  being  Deducted).     (Sir  H.  Roscoe.) 


Description  of  Fuel. 

Percentage  Composition. 

C. 

H. 

N  and  O. 

1.  Woody  fibre      
2.  Peat  from  the  Shannon    .     . 
3.  Lignite  from  Cologne      .         .     . 
4.  Earthy  coal  from  Dax  . 
5.  Wigan  cannel  
6.  Newcastle  Hartley 
7.  Welsh  anthracite      .... 

52-65 
60-02 
66-96  * 
74-20 
85-81 
88-42 
94-05 

5-25 

5-88 
5-24 
5-89 
5-85 
5-61 
3-38 

42-10 
34-10 
27-76 
19-90 
8-34 
5-97 
2-57 

The  above  shows  the  alteration  in  composition  which  wood  has 
undergone  in  passing  into  coal. 

Average  carbon  in  average  gas  coke  equals  88  per  cent.  Average 
carbon  in  average  anthracite  equals  90  per  cent. 

The  0  in  purified  coal  gas  does  not  result  from  the  distillation  of 
the  coal,  but  must  have  been  admitted  with  the  air  either  inten- 
tionally or  accidentally. 

Gas  only  forms  about  15  per  cent,  of  the  total  products  obtained 
from  the  distillation  of  coal. 

Experiments  on  small  quantities  of  coal  usually  give  results  7 
per  cent,  in  favour  of  the  coal  over  working  results. 

Sulphur  in  Coal.     (J.  Hepworth.) 


Sulphur  in  Volatile 
Products  per  Ton 
of  Coal. 

Sulphur  in  Coke 
per  Ton  of 
Coal. 

Total  Quantity  of 
Sulphur  per  Ton 
of  Coal. 

'eS 
O 
O 

Q 

A 
B 
C 
D 
E 
F 

Lbs. 
4-35 
7-84 
4-70 
18-16 
9-18 
9-04 

Percentage. 
•19 
•35 
•21 
•81 
•41 
•44 

Lbs. 
8-51 
4-92 
7-61 
15-0 
6-04 
7-76 

Percentage. 
•38 
•21 
•34 
•67 
•27 
•31 

Lbs. 
12-86 
12-76 
12-31 
33-16 
15-22 
16-80 

Percentage. 
•57 
•56 
•55 
•48 
•68 
•75 

Average  sulphur 
Left  in  coke 
Removed  by  p 
Coal 

per  ton  of  coal,  13-80  Ibs. 
.     .     6-53  Ibs 

urification  from  volatile  products    .     7*27    „ 

...... 

.  13-80    „ 

s  coals  contain  sulphur,  principally  combined  with  iron, 
of  bisulphide  of  iron  (FeS2)  or  pyrites  which  become 


Bituminous 
in  the  form 
sulphide  or  protosulptiuret  of  iron  (FeS)  on  the  application  of  heat. 

Coal  gas  contains  about  7  per  cent.  CO. 

*  According  to  the  Gas  Referee's  Reports  gas  always  contains  about 
10  grains  sulphur  per  100  cubic  feet  when  sent  out. 

The  whole  of  the  sulphur  in  coal  gas  is  converted  into  sulphur 
dioxide  during  combustion.     (W.  C.  Young.) 


GRAINS   OF    BARIUMSULPHATE    CORRECTED. 


383 


Diagram  showing  Grains  of  Sulphur  per  109  Cubic  Feet  for  each 
Grain  of  Barium  Sulphate  (corrected  for  Temperature  and  Pressure) . 


Tabular  Numbers. 

1040      IO2O      IOOO       980       960       940       920 


900 


451 


35 


8     I 


5    g 
O 


384  GAS  ENGINEER'S  POCKET-BOOK. 

To  Estimate  Lbs.  of  Prussian  Blue  in  Gallons  of  Cyanogen 
Liquor. 

Filter  small  quantity  of  liquor,  take  5  cubic  centimetres,  acidify 
with  dilute  HC1  (1  part  HC1,  H  H20),  precipitate  the  Prussian  blue 
with  a  slight  excess  of  Fe2Cl6  (ferric  chloride)  solution. 

Collect  precipitate  on  tilter,  wash  till  free  from  acid,  and  dry  at 
100°  C. 

Wash  the  dried  precipitate  with  previously  dried  CS2  (that  is  CS2 
not  in  contact  with  water)  and  allow  to  stand  until  the  CS2  has 
drained  off  or  evaporated,  and  return  it  to  drying  oven  until  quite 
dry  ;  cool  and  weigh. 

Weight  in  gas  X  2  =  pounds  per  gallon. 

Per  cent,  of  HCNS  2-62,  NH3  1-87,  K4  FeCy6  +  3aq  5'10,  from 
analysis  of  twelve  samples  of  spent  oxides  in  Germany.  (J.  V.  Esop.) 

Some  of  the  N  in  the  coal  combines  with  two  equivalents  of  carbon 
to  form  cyanogen,  which  unites  with  sulphide  of  ammonium  to  form 
sulphocyanide  of  ammonium. 

If  spent  oxide  be  burned  for  making  H2S04  the  cyanogen  com- 
pounds cannot  be  recovered. 

Spent  oxide  has  been  found  to  contain,  with  25  per  cent,  sulphur, 
12J  per  cent.  Prussian  blue. 


ENRICHING    PROCESSES.  385 

ENRICHING  PROCESSES. 

Relative  Cost  of  Enrichment  from  16  Candles  to  17-5. 

(Professor  Lewes,  1891.) 

By  Cannel  (Livesey)    4'OOd.  =  2-667^.  per  candle  per  1,000  cubic  feet 
„  Pintsch  gas  .         .     3  64     =  2-427  „  „  „ 

„  Oil  gas  (Foulis)  .     2-34     =  1-560  „  .,  „ 

.,  Maxim- Clark  pro- 
cess      .         .     .     1-64     =  1-093 
.,  Carburetted  water 

gas    .         .        .     1-01     =0-673  „  .,  „ 

..  Tatham    Oxy -oil 

process  (probable)     0'91     =  0-607  „  „  „ 

„  Tatham    Oxy -oil 

process  (claimed)    0'50     =  0-333  „  „  „ 

Peebles  process  said  to  give  1,750  candles  per  gallon. 
Water  gas  process  said  to  give  1,400  candles  per  gallon. 
Carburine,  gasoline  and  benzol  said  to  give  1,600  candles  per  gallon. 
Pintsch  gas,  liquid  from  compression,  said  to  give  3,000  candles 
per  gallon. 

Gas  enriched  1  Candle  by  1  Gallon  of  the  Liquid. 

Benzol  (chemically  pure)          ....  13,300  cubic  feet. 

Benzol  (90  per  cent.)  12,500          „ 

Carburine  (specific  gravity  '680)       .         .         .     5,700          „ 
Common  petroleum  spirit  (specific  gravity -700)    4,300          „ 

(T.  Stenhouse.) 

With  5  per  cent,  petroleum  vapour  there  is  no  danger  of  explosion  ; 
with  6-25  per  cent,  a  feeble  report;  with  8-30  per  cent,  a  loud 
report ;  with  11  to  14  per  cent,  a  violent  report ;  with  20  per  cent,  no 
explosion.  (Journal  of  Gas  Lighting.') 

70  per  cent,  by  bulk  of  producer  gas  lowers  the  flame  temperature 
of  water  gas  400°.  (Walter  Clark.) 

The  lower  the  gas  in  illuminating  power  the  more  it  costs  to 
improve  it. 

Mr.  Foulis  considers  undiluted  oil  gas  is  better  for  enrichment  and 
more  economical  than  carburetted  water  gas. 

In  distilling  shale  oil  the  gas  has  to  be  rapidly  drawn  off,  or  it 
would  become  permanent. 

Oxygen  (up  to  \  per  cent.)  added  to  pure  gas  increases  the  illu- 
minating power  (see  Gas  Journal,  1885,  "  Midland  Association  "). 
(B.  W.  Smith.) 

Formula  to  find  Proportion  of  Enriching  Gas  Required. 

Initial  candle-power  co  candle-power  desired 

~  Initial  candle-power  oo  candle-power  of  enriching  gas 

=  percentage  required. 
a.E.  o  o 


386 


GAS   ENGINEER  8    POCKET-BOOK. 


Formula  to  find  Quantity  in  Cubic  Feet  to  be  added  to  Initial 
1,000  Cubic  Feet. 


1,000  ~ 


Initial  candle-power  <x>  candle-power  desired 
Candle-power    of   enriching  gas   <x>   candle-power  desired 
=  quantity  in  cubic  feet  per  1,000. 

If  gallons  carburine  (specific  gravity  68)  per  10,000  cubic  feet  gas 
required  to  enrich  1  candle  by  Clark  carburettors. 


Enriching  Value  of  Oil  Gas  due  to  Temperature  of  Distillation. 
(W.  Foulis.) 


Coal  Gas. 
Illuminating 
Power,  cor- 
rected to  5 
Cubic  Feet 
per  Hour. 

Oil  Gas. 
Illuminating 
Power,  cor- 
rected to  5 
Cubic  Feet 
per  Hour. 

Percentage 
of  Oil  Gas 
added. 

Illuminating 
Power  of 
combined  Gas 
corrected  to  5 
Cubic  Feet 
per  Hour. 

Enrichment 
Value  of  Oil 
Gas   calcu- 
lated to  5 
Cubic  Feet. 

Average 
Retort 
Tempera- 
ture. 

20-74 
20-45 
18-51 
16-84 
14-65 

64-05 
60-88 
62-11 
61-10 
74-00 

4-20 
4-90 
4-52 
4-38 
4-00 

24-28 
23-69 
21-59 
20-85 
19-77 

105-20 
86-60 
86-60 
108-30 
117-00 

1.100°  V. 
1,135°  F. 
1.145°  F. 
1,070°  F. 
1,000°  F. 

Gasoline  boils  at  about  40°  C. 

Carburine  boils  at  about  67°  C.     Specific  gravity  0-680. 

Benzene  boils  at  about  80-5°  C.     Specific  gravity  0-885  at  15°  C. 

Kussian  mineral  oil  ('908  specific  gravity)  contains  20'5  grains 
sulphur  per  gallon. 

Russian  burning  mineral  oil  contains  10*3  grains  sulphur  per  gallon. 

American     „  „  „         16*3      ,,  „  „ 

American  water  white  mineral  oil  contains  8'1  grains  sulphur  per 
gallon. 

American  burning  safety  mineral  oil  contains  14*0  grains  sulphur 
per  gallon. 

Scotch  mineral  oil  (for  gas  making)  contains  49'S  grains  sulphur 
per  gallon.  (W.  Fox  and  D.  G.  Riddick.) 

Petroleum  contains  about  85  per  cent.  C,  13  per  cent.  H,  2  per 
cent.  0  ;  specific  gravity  '87  ;  weight  8'7  Ibs.  per  gallon. 

Petroleum  oil  contains  about  73  per  cent.  C,  27  per  cent.  H  ; 
specific  gravity  '71  ;  weight  7*10  Ibs.  per  gallon. 

162  cubic  feet  of  16-candle  gas  will  retain  the  vapour  from  1  gallon 
carburine  at  59°  F.,  and  30  inches  pressure.  (Professor  W.  Foster.) 

Where  cannel  is  used  for  enrichment  there  is  seldom  much 
napthalene  deposited. 

To  produce  gas  from  iron  and  steam,  for  every  1,000  cubic  feet 
hydrogen  produced,  rather  less  than  1  cwt.  iron  would  be  required, 
(H.  Kendrick.) 


BENZOL   AS   AN    ENHICHEH.  387 

The  "Browne"  Process  of  Making,  Lighting,  and  Heating  Gas  from 
Crude  Petroleum. 

An  emulsion  of  5  or  6  volumes  of  crude  petroleum  is  made 
with  95  or  94  volumes  of  water.  This  emulsion  is  pumped  slowly 
through  a  tube  about  300  feet  long  under  a  pressure  of  100  Ibs, 
on  the  square  inch.  One  end  of  the  tube  is  at  the  temperature 
of  the  air,  the  other  is  sufficiently  hot  to  bring  about  chemical 
action  between  the  vaporised  contents,  and  hydrogen  and  carbon 
monoxide  are  liberated  as  permanent  gases  that  are  then  passed 
through  a  coke-water  scrubber  and  may  afterwards  be  stored 
in  a  holder  for  use.  The  heat  applied  to  the  converting  tube  increases 
gradually  from  end  to  end.  The  light-giving  value  of  the  gas  can  be 
raised  by  allowing  a  greater  proportion  of  petroleum  to  be  added 
when  about  half-way  through  the  converting  tube. 

Mixtures  of  ethylene  and  oxygen  in  insufficient  quantity  to  form 
explosive  mixtures  possess  greater  illuminating  power  than  pure 
ethylene,  the  highest  luminosity  observed  being  with  75  per  cent, 
ethylene  and  25  per  cent,  oxygen.  An  increase  of  oxygen  above  this 
diminished  the  illuminating  power. 

Wood  Gas. 

One  retort  about  21  inches  diameter  by  9  feet  6  inches  long  will 
produce  12,000  cubic  feet  per  day. 

One  ton  of  wood  will  produce  8.000  to  11,000  cubic  feet,  of  9  to  16- 
candle  gas.  Eesiduals,  charcoal  4  cwt.,  tar  1^  cwt. 

Benzene  is  as  500  to  900  candles  per  5  cubic  feet  vapour,  compared 
with  napthalene.  (Professor  V.  B.  Lewes.) 

Benzene  is  probably  not  efficient  when  the  gas  requires  enriching 
more  than  1  to  2  candles. 

Benzene  vapour  should  have  an  illuminating  power  of  700  candles 
per  5  cubic  feet,  with  an  enriching  value  of  3*9.  (Professor  V.  B. 
Lewes.) 

A  gallon  of  benzol  has  an  enrichment  value  of  only  4,500  candles, 
and  carburine  is  only  one-fourth  as  effective.  (Mr.  W.  Young,  of 
Peebles.) 

One  gallon  of  benzol  will  enrich  from  12,000  to  15,000  cubic  feet, 
adding  1  candle-power  to  it.  The  cost  to  enrich  1,000  cubic  feet  to 
the  extent  of  1  candle-power  with  benzol  is  from  %d.  to  Id. 

Four  to  5  candles  can  be  added  to  gas  with  600  to  700  grammes 
benzol,  and  would  be  stable  at  32°  F.  At  77°  F.  gas  will  hold  four 
times  the  quantity  of  benzol  which  it  will  at  30°  F.  (Dr.  Schilling.) 

Temperature  required  to  vaporise  benzol  =  -f-  212°  F. 

It  is  unnecessary  to  heat  benzol  when  using  it  as  an  enricher, 
except  in  very  cold  weather. 

The  molecular  structure  of  the  benzol  molecule  is  such  that,  of  all  the 
liquid  hydrocarbons  known,  it  is  the  one  which  may  be  expected  to 
break  up  most  readily.into  that  wonderful  acetylene,  which,  according 
to  some  authorities,  puts  everything  into  the  shade  as  a  light  pro- 
ducer. (T.  Steiihouse.) 

Vapour  tension  of  benzene  (90°  benzol)  at  59°  F.  equals  58'9  milli- 
metres. 

002 


388  GAS  ENGINEER'S  POCKET-BOOK. 

1,000  parts  of  water  dissolve  1*45  parts  of  benzene,  0*57  parts  of 
toluene,  and  0*12  part  of  xylene. 

Benzene  can  be  obtained  by  keeping  acetylene  for  a  long  time  just 
below  a  red  heat.  (Professor  Mills.) 

From  Manchester  gas  3 '7  to  4-25  gallons  of  liquid  per  10,000  cubic 
feet  were  dissolved  out,  containing  80  per  cent,  hydrocarbons  of  the 
benzene  series  (1884),  with  an  enrichment  value  of  4,500  candles  per 
gallon.  (Gr.  E.  Davis.) 

At  least  three  times  the  amount  of  petroleum  spirit  is  required  to 
repair  the  loss  of  a  certain  quantity  of  benzene,  and  there  is  also  a 
great  difficulty  in  getting  the  required  amount  into  the  gas  without 
condensation.  (Wilfred  Irwin.) 

One  cubic  foot  gas  will  permanently  retain  alone  50  grains  benzol 
vapour  at  a  temperature  of  32°  F.  (T.  Stenhouse.) 

Average  Specific  Gravities  of  Commercial  Benzols. 
90  per  cent,  benzol ....  0*880  to  0-883 


50 
0 
Solvent  Naphtha  90  per  cent,  at  160°  C. 


Heavy  naphtha  . 
Pure  benzene  . 
Toluene 
Xylene 


170°  C. 


0-875  to  0-877 
0-870  to  0-872 
0-874  to  0-880 
0-890  to  0-910 
0-920  to  0-945 
0-883  to  0-885 
0-870  to  0-871 
0-867  to  0-869 


One  candle  enrichment  per  gallon  with  benzol. 

C.  Hunt          gives    ....      9500  cubic  feet. 
Schilling  .,  .        .        .     .     15600    „ 

J.  F.  Bell  '„....    20000    „        „ 

Dr.  H.  Bunte     „  ....    24500    „        „ 

One  cubic  foot  benzol  equals  40  candles  (L.  T.  Wright). 

,,  „  „      147       „       (Professor  Falkland). 

„  ,,  ,,184      „       (Knublauch). 

The  higher  the  percentage  of  methane  the  greater  the  power  of 
absorbing  benzol. 

Benzene  freezes  at  32°  F.,-and  boils  at  177°  F. ;   specific  gravity  at 
60°  F.  0-8833. 

Each  grain  absorbed  per  cubic  foot  of  common  gas  increases 
illuminating  power  10  per  cent.     (Letheby.) 

Enrichment  per  Gallon  per  10,000  Cubic  Feet  with  Benzene. 

Candles 
Enrichment. 

Bunte  gives 3-6 

Frankland        „  2-9 

Hunt  „         .        .        .  -         -    0-9 

Knublauch       „  • JJ 

Stenhouse         „ 1*3 

L.T.Wright    „  ....  -0-8 

W.  Irwin  .,      with  flat  flame  burner 

„    Argand         „        .    .    0'5 


BENZOL   AS   AN    ENRTCHER.  389 

To  enrich  with  benzol,  the  coal  gas  is  made  to  pass  over  the  surface 
of  cold  benzol,  and  the  vapour  rising  from  this  is  taken  up  and  com- 
bines with  the  gas  at  once,  the  quantity  absorbed  being  regulated  by 
the  area  of  benzol  surface  exposed  and  the  rate  at  which  the  gas  passes 
through  the  benzoliser. 

Gas  enriched  to  17  or  18  candles  with  benzene  would  be  far  better 
appreciated  by  the  average  consumer  than  20-candle  gas  owing  its 
illuminating  power  largely  to  olefines. 

Benzol  will  separate  when  the  gas  is  exposed  to  great  cold.  (Dr. 
Buel.) 

Commercial  benzol  if  used  for  enrichment  may  contain  sufficient 
sulphur  to  cause  an  increase  of  10  grains  S  per  100  cubic  feet  of  gas 
per  1  candle  of  enrichment. 

Ninety  per  cent,  benzol  contains  25  per  cent,  toluol,  therefore  it  is 
best  to  use  the  purest  benzol  for  enriching,  as  the  evaporation  is  not 
so  rapid  with  toluol,  nor  the  enriching  value  so  great. 

The  higher  the  boiling-point  of  the  paraffin  series  of  hydrocarbons 
the  greater  is  their  enriching  value.  (Wilfrid  Irwin.) 

While  for  carburetting  feebly  illuminating  coal  gas  about  8-8 
grains  of  benzol  or  toluol,  or  31-7  grains  of  pentane  or  hexane  per 
candle  per  hour  are  required,  with  hydrogen  double  the  quantity 
is  required,  and  with  carbonic  oxide  treble  is  required.  (Dr.  H. 
Bunte.) 

Candle  Cubic 

Enrich-  Feet  of 

ment.  Gas. 

1  gallon  pure  benzol =  1  per  13,300 

1      „      commercial  benzol =  1    „  12,500 

1       „       carburine  (-689  specific  gravity)      .         .     .     =  1    „  5,700 

1      „      common  petroleum  spirit(-700  specific  gravity)  =1    „  4,300 

(T.  Stenhouse.) 

Gas  will  carry  3  per  cent,  benzol  at  32°  F.     (Dr.  Bunte.) 

0-0033  gramme  per  litre  per  candle  enrichment  is  required  with 
toluene. 

0*0034  gramme  per  litre  per  candle  enrichment  is  required  with 
benzene. 

0*0028  gramme  per  litre  per  candle  enrichment  is  required  with 
benzene  and  H. 

0*0115  gramme  per  litre  per  candle  enrichment  is  required  with 
heptane. 

0-0027  gramme  per  litre  per  candle  enrichment  is  required  with 
xylene. 

0-0026  gramme  per  litre  per  candle  enrichment  is  required  with 
napthalene  and  H. 

0-0020  gramme  per  litre  per  candle  enrichment  is  required  with 
napthalene. 

0-0064  gramme  per  litre  per  candle  enrichment  is  required  with 
phenol.  (W.~  '  ' 


390 


GAS  ENGINEER'S  POCKET-BOOK. 


To  Test  between  Petroleum  Benzene  and  Benzene  from  Coal  Tar. 

Use  Syrian  asphalte  washed  thoroughly  with  petroleum  naptha  to 
remove  all  constituents  soluble.  The  colour  of  the  mixture  of  the 
two  benzenes  after  treatment  with  the  asphalte  varies  from  straw 
colour  to  dark  brown  according  to  the  quantity  of  the  coal  tar 
benzene  present,  and  these  colours  can  be  made  to  indicate  the 
proportion  of  each  benzene  in  the  mixture.  (Journal  of  the  Society 
of  Cliemical  Industry.") 


Value  of  Acetylene  as  an  Enriclier  of  Coal  Gas. 
(Professor  V.  B.  Lewes.) 


Composition  of  the  Mixture. 

Illuminating  Value. 

Enrichment 
Value  of 
1  Per  Cent,  in 
Candles. 

Coal  Gas. 

Acetylene. 

Coal  Gas. 

Mixture. 

99-10 

0-90 

13 

13-9 

l-Oo 

97-90 

2-10 

13 

15-1 

i-oo 

96-00 

4-00 

13 

17-3 

1-07 

95-20 

4-80 

13 

18-4 

1-12 

91-00 

9-00 

13 

23-5 

1-16 

89-50 

10-50 

13 

25-3 

1-17 

85-00 

15-00 

13 

33-0 

1-33 

83-25 

16-75 

13 

36-1 

1-36 

66-90 

33-10 

13 

60-5 

1-43 

55-50 

44-50 

13 

76-7 

1-43 

16-70 

83-30 

13 

175-2 

1-94 

oo-oo 

100-00 

0 

240-0 

2-40 

The  theoretical  yield  of  acetylene  is  25  Ibs.  per  60  Ibs.  of  carbide 
approximate — more  correctly,  26  Ibs.  to  64  Ibs. 

The  following  data  for  a  1,000  horse-power  engine  are  based  on  the 
estimates  of  D.  Adolph  Frank,  of  Charlottenberg,  and  are  intended 
to  show  the  saving  in  space  obtained.  The  engine  is  supposed  to  be 
run  for  600  hours,  and  at  1-54  Ib.  of  coal  per  horse-power  per  hour 
would  require  about  420  tons,  which  would  occupy  about  as  many 
cubic  metres.  Liquid  acetylene  at  39  Ibs.  per  horse-power  per  hour 
would  weigh  about  108  tons,  and  occupy  about  300  cubic  metres, 
while  carbide  of  calcium  with  36  per  cent,  by  weight  of  acetylene, 
need  not  occupy  much  more  than  150  cubic  metres,  even  after 
allowing  for  protective  apparatus.  In  the  latter  cases  the  space 
occupied  at  present  by  the  boilers  would  not  be  required. 

Acetylene  with  different  proportions  of  air  gives  the  following 
results  :  When  1,000  cubic  inches  of  the  mixture  contain  less  than 
77  cubic  inches  of  acetylene,  it  will  burn  completely,  producing 
water  and  carbon  dioxide.  When  the  proportion  of  acetylene  is 
increased  so  that  it  forms  from  77  to  174  cubic  inches  per  1,000  of 
the  mixture,  the  product  consists  of  water,  carbon  dioxide,  carbon 


ACETYLENE. 


391 


monoxide  and  hydrogen,  and  the  combustion  is  therefore  imperfect. 
With  larger  proportions  of  acetylene  free  carbon  and  unaltered 
acetylene  are  left.  When  anything  between  28  and  650  cubic  inches 
of  acetylene  are  present  in  1,000  of  the  mixture  it  will  take  fire. 
(M.  Le  Chatelier.) 

Calcium  carbide,  CaCa  -f  HaO  =  C2Ha  +  CaO. 

1  Ib.  CaC2  makes  about  6  cubic  feet  acetylene  (C2H2)  of  about 
48  candle-power  per  foot. 

10  volumes  water  will  absorb  11  volumes  acetylene  gas  at  ordinary 
temperature  and  pressure. 

Iron  burners  are  not  suitable  for  use  with  acetylene  gas,  as  the  gas 
destroys  the  metal  and  enlarges  the  holes. 

Gas  is  evolved  from  calcic  carbide  until  a  pressure  of  1,100  Ibs, 
per  square  inch  is  present. 

87£  Ibs.  lime  to  56J  Ibs.  C  yield  100  Ibs.  calcium  carbide  and 
43f  Ibs.  CO. 

100  Ibs.  carbide  yields  40*62  Ibs.  acetylene  and  115-62  Ibs.  slaked 
lime,  or  5*9  cubic  feet  of  acetylene  per  Ib.  carbide. 

Calcic  carbide  has  specific  gravity  2-262. 

„  „       is  liquefied  at  '52°  F.  by  a  pressure  of  21^  atmospheres. 

1  Ib.  liquefied  calcic  carbide  will  expand  to  14£  cubic  feet  at 
atmospheric  pressure. 

Space  required  in  generator  80  cubic  inches  per  1  Ib.  carbide. 

1  volume  acetylene  -f-    1£  volumes  air  is  slightly  explosive. 

1       »  ,»          +  12         „  „     very    *          „ 

1       „  „          +20         „  „     not 

Acetylene  or  ethine  (C2H2)  is  colourless,  and  burns  with  an 
intensely  luminous  flame,  of  the  odour  of  rotten  vegetables.  Is  made 
by  the  action  of  H20  upon  calcium  carbide  (CaC2),  the  latter  the 
produce  of  carbon  and  calcium  burnt  in  an  electrical  furnace. 

Acetylene  has  approximately  15  times  the  lighting  value  of 
common  gas,  but  has  only  two  and  a  half  times  the  heating  value. 

Heat  from  1  Ib.  carbide  during  conversion  to  C,H9  will  boil  6  Ibs 
H20. 

The  Toxicity  of  Acetylene. — M.  Grehant  found  it  is  poisonous  if 
inhaled  in  l.-n-ge  quantities  between  40  and  79  per  cent. 

The  amount  of  acetylene  in  Manchester  gas  never  exceeds  0*05 
per  cent. 

6-35  cubic  feet  C2H2  gives  1  H.P. 

Specific  gravity  C.2H2  =  0-91. 

1  foot  C2H2  weighs  about  ;0688  Ibs. 

Comparison  of  Illuminating  Value  to  Proportions  of  Acetylene. 
(Professor  V.  B.  Lewes.) 


Analysis  of  Mixture. 

Acetylene  at  Top 
of 
Non-luminous  Zone. 

Illuminating  Value 
of  Flame 
per  5  Cubic  Feet. 

H. 

Acetylene. 

65-5 
43  -5 

o-o 

34-5 
56-5 

100-0 

3-72 

8-42 
14-95 

14-0 
87-0 
240-0 

392 


GAS  ENGINEER'S  POCKET-BOOK. 


Purified  Lowe  oil  gas  contains  :— 

H 

Saturated  hydrocarbons,  methane,  &e. 
„         carbon,  ethylene,  &c.  . 

CO 

0 

N 


22-6 

31-9 

13-4 

29-2 

0-6 

2-3 


100-0 

(Professor  Lewes,  1893.) 


Average  Composition  of  Water  Gas  (Non-luminous). 
(Professor  Lewes.) 

H  .        .  48-31  per  cent.  Methane  .       T05  per  cent. 

CO          .     .  35-93        „  H2S        .  .       1-20 

C02  .         .      4-25        „  0  0-51        „ 

N    .  8-75 


Analysis  of  Water  Gas.     {Lancet). 


Hydrogen  (H) 
Methane  (CH4)  . 
Carbon  monoxide  (CO) 
Carbonic  acid  (C02)    . 
Nitrogen  (N)  . 


Per  Cent, 
by  Volume. 
.     49-17 
.       0-31 
.     43-75 
.      2-71 
4-06 


26  candle-power  water  gas  consists  of  : — 

Per  Cent, 
by  Volume. 

Hydrogen 34 

Methane 15 

Hydrocarbons  absorbable  by  fuming  sulphuric  acid    .     12-5 

CO 33 

Nitrogen from  0-5  to  5 

Specific  gravity  equals  0'62  (air  1).     (Butterfield.) 


Analysis  of  Carburetted  Water  Gas  at  Outlet  of  Exhausters. 


C02      . 

CO. 

CnH2n 

CH4 

H 

O    . 

N 


4-6 

14-8 

21-2 

30-7 

18-4 

1-0 

9-3 

100-0 


CARBURETTED  WATER  GAS  PLANT.          393 

Generator  of  £  million  plant,  generally  18  feet  high,  10  feet 
diameter,  with  fire  bars  4  feet  from  bottom,  with  4  cleaning  doors 
8  feet  from  bottom,  the  upper  portion  coned  to  an  opening  about 
2  feet  diameter. 

Carburettor  same  size,  but  no  doors,  filled  with  checker  bricks. 

Superheater  24  feet  high,  10  feet  diameter,  also  filled  with  checker 
bricks  up  to  within  4  feet  from  top. 

Scrubber,  20  feet  high,  6  feet  diameter,  filled  with  layers  of  wood 
strips  placed  checkerwise. 

Condenser,  20  feet  high,  6  feet  diameter,  filled  with  2-inch  tubes. 

The  generator,  carburettor,  and  superheater  are  usually  lined  with 
fire-clay  blocks  10  inches  thick,  with  space  of  2  inches  between  shells 
and  bricks,  tightly  packed  with  a  non-conductor.  The  blast  inlet  to 
the  generator  is  below  the  fire  bars,  where  the  steam  is  also  admitted. 
The  blast  inlet  to  the  carburettor  is  at  the  top,  and  to  the  superheater 
at  the  bottom. 

Superheater  usually  6  to  8  feet  higher  than  the  carburettor. 

Maximum  pressure  in  shells,  ordinary  working,  40  inches  water. 

Average          „  „  „  30      „          „ 

Pressure  at  which  shells  should  be  gas  tight,  3  Ibs.  per  square 
inch. 

Pressure  of  air  blast,  12  to  15  inches  of  water. 

Pressure  of  steam,  130  Ibs.  per  square  inch. 

Blast  mains  usually  No.  18  Birmingham  wire  gauge  galvanized 
iron  ;  average  blast  14  inches  water. 

Blowers  usually  work  2,000  revolutions  per  minute. 

Temperature  in  generator  should  not  be  allowed  to  get  below 
1,000°  C.,  and  fuel  of  sufficient  depth  to  convert  the  C02  to  CO, 
provided,  and  the  C  should  be  in  excess.  Best  temperature,  about 
1,100°  C. 

Superheater  must  be  kept  at  a  temperature  just  below  that  required 
to  separate  the  C  from  the  oil  vapours. 

Gradually  increasing  heats  in  carburettor  and  superheater  best  for 
fixing  oil  gas.  Oil  injected  at  from  25  to  30  Ibs.  per  square  inch. 

Too  low  heats  give  a  tarry  stain  on  white  paper  held  to  pet  cock  on 
superheater. 

Too  high  heats  give  a  deposit  of  carbon  particles  on  white  paper 
held  to  pet  cock  on  superheater. 

Coke  for  feeding  generators  should  be  of  even  size  and  screened, 
giving  little  ash  so  that  the  steam  may  not  pass  through  the  fuel  too 
freely.  Coke  must  be  fed  regularly,  say  every  two  hours. 

Superheated  steam  obtained  by  use  of  boilers  working  at  130  Ibs. 
pressure. 

Blast  pipes  are  often  made  of  16  Birmingham  wire  gauge,  and  are  all 
connected  by  small  pipes,  so  that  the  pressure  is  in  all  even  when  the 
fans  are  not  running  in  every  set. 

Two-inch  safety  tube  is  fixed  just  outside  blast  valve,  so  that  if  oil 
is  leaking  back  through  blast  stop- valves  on  vessels  the  pressure 
causes  a  smoke  to  issue  from  the  tube. 

One  foreman  superintends  the  work  of  gas  making  and  clinkering. 

A  gang  of  four  men  clinker  three  fires  twice  during  eight-hour  shift. 


394  GAS  ENGINEER'S  POCKET-BOOK. 

A  safety  valve  is  fixed  outside  each  blast  inlet  valve  of  the  same 
bore  as  the  pipe. 

Seal  in  seal  pot,  3  inches. 

Tubes  in  condenser  which  comes  after  the  scrubber,  1£  inches 
diameter. 

In  lighting  up,  fill  up  generator  with  coke  and  open  the  stack 
valve,  shut  generator  charging  door  and  turn  on  blast  at  generator  ; 
when  the  brickwork  of  carburettor  is  red  hot  turn  on  blast  there  until 
superheater  is  red  hot,  and  then  put  blast  there  until  all  are  cherry 
red  hot. 

If  coke  is  required  in  generator  before  all  are  hot,  shut  all  blast  off 
and  close  stack  valve,  and  then  open  charging  door. 

In  working,  shut  off  blast  first  from  generator,  then  carburettor, 
and  then  superheater,  shut  stack  valve,  then  open  oil  feeder,  and 
next  turn  on  steam  to  generator  and  oil  pumps. 

When  gas  making  is  finished,  shut  off  oil,  then  steam  to  generator, 
open  stack  valve,  and  then  open  blast  on  superheater,  carburettor, 
and  generator. 

Average  fuel  required  per  1,000  cubic  feet  gas  made,  45  Ibs. 

Average  oil  required  per  1,000  cubic  feet  gas  made  (distillate  from 
Russian  crude),  5'46. 

Candle  power  per  gallon  oil  developed,  9-03. 

Percentage  volume  C02  in  crude  gas,  4  per  cent,  by  volume. 

Illuminating  power  of  gas,  24 '68  candles. 

Low  heats  or  excess  steam  produce  increase  of  C02. 

Half  million  per  day  plant  can  be  started  in  full  working  order  in 
3£  hours. 

Temperature  at  which  C  decomposes  water  vapour  to  C02  and 
2  H2  equals  600°  C. 

Temperature  at  which  C  decomposes  water  vapour  to  CO  and 
H2  equals  1,000°  C. 

When  steam  superheated,  or  at,  say,  130  Ibs.  per  square  inch,  is 
passed  through  fuel  at  1,000°  C.,  CO  -j-  H2  are  formed  with  about  3 
per  cent.  C02. 

To  avoid  explosions  when  lighting  up,  fill  the  generator  to  the  top 
with  fuel  under  slow  fire  without  blast,  and  when  blast  is  put  on  do 
not  open  the  generator  until  it  is  at  a  working  heat. 

Checker  work  requires  renewing  every  six  months  (about)  and 
should  have  superficial  area  of  16  square  feet  per  1,000  cubic  feet 
made  per  diem,  not  including  linings. 

By  superheating,  a  considerable  increase  of  illuminating  power  can 
be  obtained  with  either  crude  petroleum  (naptha)  or  pure  paraffins. 
(Dr.  H.  Bunte.) 

The  quantity  of  water  gas  produced  from  1  Ib.  of  carbon  is  about 
61  cubic  feet  at  600°  F.,  and  to  produce  this  4,200  heat  units  are 
absorbed,  or  about  70  units  per  cubic  foot. 

With  carburetfced  water  gas  on  a  commercial  scale  1,000  cubic  feet 
of.22-candle  gas  can  be  produced  from  50  Ibs.  coke  and  4  gallons 
oil*. 

Mix  rich  gases  with  poor  ones  as  early  as  possible  during  manu- 
facture. 


ANALYSES    OF    CARBURETTED    WATER     GAS.  395 


Analysis  of  Heating  Gases 

Outlet  of  Outlet  of 

Producer,  Superheater. 

C02         .        .        .        .        7-94  .        .      15-10 

CO 23-21    .  .     .        0-10 

O             ....         —  ..        3-80 

N 68-85    .  .    .       81-00 

Proportions  of  C02  per  Minute  of  Bun. 
Minutes         12345        Average. 
C08  .        .     0-5         1-7        4-1          6-2          7-9  4'05 

Percentage  of  CO.,  at  End  of  Each  Minute  of  a  Five  Minutes'  Bun, 
at  Outlet  of  Generator.    (Butterfield.) 
1st  minute  =  0-3  per  cent.  COa 
2nd       „      =  0-6        „ 
3rd       „       =  1-4        „ 
4th        „       =  2-6        „ 
5th        „      =  4-2        „ 

Average       1-82 

Proportion  of  COa  increases  according  to  length  of  run. 

C02  in  water  gas  varies  from  1^  to  4  per  cent. 

Only  3  per  cent.  C02  should  be  present  in  water  gas,  as  it  reduces 
the  illuminating  power  of  the  gas. 

Percentage  of  C02  in  uncarburetted  water  gas  usually  4  to  5  per 
cent. 

CS2  in  carburetted  water  gas  is  about  4  grains. 

CO  in  crude  carburetted  water  gas  at  Blackburn  equals  28  or  29 
per  cent. 

Analysis  of  Crude  Carburetted  Water  Gas.    (Paddon  and  Goulden.) 
(Class  of  oil  used,  a  rough  distillate  from  Kussian  crude.) 


H     .  21-8 


H2S  and  C02           .        .        3-8 
O 0-5 

N     .  2-2 


CH4 30-7 

CnH2N    ....      12-9 

CO 28-1 

At  Blackburn,  the  total  of  five  experimental  runs  with  water  gas 
(carburetted),  17,560,000  cubic  feet  gas  of  22-77  illuminating  power 
was  made  from  57,992  gallons  "  solar  distillate  "  -875  specific  gravity. 
648,267  Ibs.  coke  was  used,  and  1,162,000  gallons  water. 

Analysis  of  Water  Gas. 

American  English 

Practice.  Practice. 

C02                   ....        3-5        ..  3-87 

CO 43-4   .        .     .  45-87 

H 51-8        .         .  49-55 

N 1-3   ...  0-71 


396 


GAS    ENGINEER  S    POCKET-BOOK, 


Carburetted  water  gas  from  coke  should  contain  about  3  per  cent. 
C02. 

Carburetted  water  gas  from  coke  should  contain  about  2  per  cent. 
HaS. 

Sulphur  compounds  not  exceeding  10  grains  per  100  cubic  feet. 

Cost  of  purifying  Carburetted  water  gas  equals  l'043d.  per  1,000 
cubic  feet. 

Carburetted  water  gas  making  requires  only  half  the  labour  of  coal 
gas,  and  saves  -I7d.  per  1,000  cubic  feet  for  purification. 

Water  gas  can  be  enriched  at  the  rate  of  0-006  gramme  per  litre 
per  candle. 

26-candle  carburetted  water  gas  contains  60  percent,  by  volume 
of  pure  water  gas. 

26-candle  gas  is  the  most  economical  to  make. 

Enriching  value  of  20  to  25  candle-power  water  gas  (carburetted) 
equals  about  20  per  cent,  more  than  its  nominal  value.  (J.  Methven.) 

Water  gasper  se  has  not  any  illuminating  power. 

Solar  distillate  has  specific  gravity  about  -875  of  flashing  point 
170°  P. 

Solid  residue  from  oil  should  not  exceed  2  per  cent,  by  weight. 

Water  required  for  condensing  carburetted  water  gas  equals  90 
gallons  per  1,000  cubic  feet.  (A.  G.  Glasgow,  1892.) 


Approximate  Analysis  of  Oil  Gas  Tar,  from  Condensers. 

(Paddon  and  Goulden.) 
Special  gravity  of  Tar  -996. 


Per  Cent,  by 
Volume. 

Per  Cent,  by  Volume 
Without  Water. 

Water       

76-5 

Benzene       

0-28 

1-19 

Toluol      

0-90 

3-83 

Light  paraffins,  &c.      .        .     . 
Solvent  naptha  (zyloete) 
Phenol         .        .        .... 

2-0 
4-15. 
only  a  trace 

8-51 
17-96 
only  a  trace 

Middle  oils  (naptha,  &c.) 
Creosote  oil  and  green  oil   .     . 
Napthalene      .... 

6-92 
5-70 
0-30 

29-44 
24-26 
1-28  per  cent,  by 
weight 

Anthracene  cake  .    . 

0-22       contains 

0-93 

8-33  per  cent. 

anthracene 

Coke        

2-30 

9-80 

99-27 

97-20 

Loss        

,     0-73 

2-80 

100-00 

100-00 

CARBTJRETTED    WATER    GAS    TAR,  397 

Carburetted  water  gas  tar  contains  about  70  per  cent,  water  as  it 
leaves  the  apparatus. 

Water  used  for  cooling  and  scrubbing  about  70  gallons  per  1,000 
cubic  feet  gas  made,  but  this  quantity  is  being  reduced  in  modern 
plants  to  about  40  gallons. 

In  America  the  production  of  oil  gas  tar  by  the  Lowe  process  is 
about  12£  per  cent,  of  the  oil  used. 

To  adequately  protect  petroleum  tanks  from  lightning,  it  is  neces- 
sary that  all  openings  through  which  vapour  can  escape  should  be 
guarded  with  wire  netting  upon  the  principle  of  the  Davy  safety 
lamp.  (Professor  Neesen.) 

Joints  in  pipes  for  petroleum  carrying  should,  preferably,  be 
screwed,  and  when  all  oil  has  been  removed  from  the  threads,  a  good 
thick  shellac  varnish  should  be  applied  to  the  outside  and  inside 
threads. 

Yellow  soap,  treacle,  honey,  glue,  mucilage,  or  glycerine  are  all 
quite  petroleum  proof.  Canvas  saturated  with  shellac  varnish  makes 
a  good  washer  and  might  be  used  as  the  strip  in  riveted  joints. 


Analysis  of  Belfast  Carburetted  Water  Gas, 


C02  

o 

.    nil. 
nil. 

Unsaturated  hydrocarbons 
CO        
Saturated  hydrocarbons    . 
H          
H 

.     10-7  per  cent. 
.     .     31-9       „ 
.     16-2      ., 
.     ,     33-7      „ 
7-5 

100-0     „ 

C02  in  crude  gas 3'5  per  cent. 

SH2     „        „  ....        -2      „ 

In  water  gas  plant,  at  end  of  first  minute  gas  should  contain  0'3  per 
cent.  C02  ;  at  end  of  second  minute  gas  should  contain  0'6  per  cent. 
CO2;  at  end  of  third  minute  gas  should  contain  1-4  per  cent.  C02 ; 
at  end  of  fourth  minute  gas  should  contain  2*6  per  cent  C02  ;  at  end 
of  fifth  minute  gas  should  contain  4*2  per  cent.  C02.  (Butterfield.) 

Crude  water  gas  from  coke  (carburetted)  will  contain  about  90  to 
150  grains  H2S  per  100  cubic  feet,  and  about  3  per  cent.  C02,  no 
ammonia,  sulphur  compounds  not  more  than  10  grains  per  100  cubic 
feet.  Purification  of  water  gas  from  C02  is  twice  that  of  coal  gas. 
(Butterfield.) 

If  air  is  forced  through  red  hot  coke,  1  Ib.  of  carbon  in  burning  to 
CO  liberates  4,451 -4  units  of  heat;  but  if  burnt  to  carbon  anhydride, 
14,544  units. 

If  there  be  sufficient  body  of  carbon  for  this  latter  gas  to  pass 
through,  it  is  decomposed  with  the  absorption  of  10,000  units  of 
heat. 


398  GAS  ENGINEER'S  POCKET-BOOK. 

One  pound  C  requires  1J  Ibs.  0,  and  forms  2j  Ibs.  CO,  but  air 
would  contain  for  1£  Ibs.  0  about  4±  Ibs.  N. 

If  steam  is  forced  through  1  Ib.  C  requires  1^  Ibs.  steam  to  form 
CO.  and  this  steam  contains  1%  Ibs.  0  and  $  Ib.  H. 

One  pound  H  burnt  to  water,  yields  62,500  heat  units,  this  -f-  6  = 
10,416  heat  units  equal  to  quantity  absorbed  by  the  hydrogen  ; 
and  less  1,723  heat  units  (the  heat  already  absorbed  by  the  steam) 
equals  8,693  units,  of  which  4,500  will  be  supplied  by  the  forming  of 
CO,  leaving  4,200  units  to  come  from  the  previously  heated  coke. 

In  practice  more  is  taken  from  the  coke,  as  the  gases  escape  hot, 
(Norton  H.  Humphreys.) 

Steam  brought  into  contact  with  an  excess  of  carbon  at  1,000°  F. 
is  decomposed  into  its  component  gases  H  and  0,  and  combines  with 
the  carbon  to  form  CO  +  H. 

Equation  of  water  gas  production — 

First  action      .       4  (H20)  +  2  C  ==  2  C02  +  8  H. 
Second  action  .        2  C02  +  8H  +  2C  =  4CO  +  8H. 

(B.  H.  Thwaite.) 

The  0  of  steam  attacks  not  only  the  surplus  carbon,  but  also  the 
hydrocarbon  when  mutually  decomposing,  as  in  water  gas  plants, 
bringing  about  the  destruction  of  a  large  quantity  of  illuminating 
matter.  (Young.) 

Ordinary  producer  gas  contains  about  30  per  cent,  by  volume  of 
combustible  gases,  and  has  a  calorific  value  of  about  £th  that  of  16- 
candle  gas. 

If  producer  and  water  gas  were  mixed  the  mixture  would  consist  of 
30-5  H,  60  CO,  and  60  N. 

Minimum  temperature  for  formation  of  pure  water  gas,  1.800°  F. 

To  form  sufficient  heat  for  the  production  of  1  volume  water  gas 
1'4  volumes  producer  gas  are  required. 

Temperature  in  water  gas  generator  should  never  be  lower  than 
1,000°  C.,  and  fuel  should  be  of  sufficient  thickness  to  ensure  as 
complete  a  conversion  of  the  C02  to  CO  as  possible. 

With  hard  anthracite  coal  it  is  possible  to  so  arrange  the  tempera- 
ture in  the  generator  that  practically  no  C02  is  formed,  but  with 
coke  a  percentage  of  the  product  is  almost  bound  to  be  produced. 
H2S  is  also  absent  when  anthracite  is  used,  as  it  is  formed  from  the 
S  in  the  coke. 

Carburetted  water  gas  plant  at  Blackburn — 

Coke  used  per  1,000  cubic  feet    30-8  Ibs.  for  generator. 
„          „          „          „  6-1    „      „    boiler. 

,/        „          „  „          36-9  total. 

Oil,  candles  per  gallon    .        .       6'97 
Oil,  specific  gravity    .        .     .        '878 

Mr.  Foulis  found  that  with  ordinary  water  gas  apparatus  he  re- 
quired 30  Ibs.  to  40  Ibs.  coke  per  1,000  cubic  feet  of  30-candle  gas 
using  6  gallons  oil. 


CALORIFIC  VALUE  OF  WATER  GAS.         399 

TJncarburetted  water  gas  has  only  about  half  the  calorific  power 
of  coal  gas,  but  when  carburetted  to  about  22  to  23  candles  is  about 
85  per  cent,  to  95  per  cent,  the  power. 

Semi  water  gas  contains  from  80  to  85  per  cent,  of  the  heating 
value  of  coal,  and  is  the  cheapest  gas  if  supplied  within  a  reasonable 
distance  from  the  place  of  production.  (A.  Kitson.) 

Water  gas  from  anthracite  coal  has  a  calorific  value  of  290  heat 
units.  Water  gas  from  bituminous  coal  has  a  calorific  value  of 
350  heat  units.  (B.  Loomis.) 

Difference  in  heating  value  of  carburetted  water  gas  and  coal  gas 
is  as  9  to  10. 

Water  gas,  hydrogen,  or  mixtures  of  the  two,  when  carburetted  by 
the  vapours  obtained  by  decomposing  hydrocarbons  yield  a  flame 
which,  although  it  may  be  of  high  illuminating  value,  is  far  shorter 
and  smaller  than  the  flame  obtained  from  ordinary  coal  gas,  and  that 
in  consequence  of  this  it  has  to  be  burnt  in  larger  quantities  in  order 
to  obtain  a  flame  which  shall  in  appearance  equal  that  of  coal  gas. 
This  is  due  to  the  coal  gas  containing  from  36  to  46  per  cent,  of 
methane,  or  light  carburetted  hydrogen,  which  gives  body  and  length 
to  the  flame,  and  which  only  exists  in  carburetted  water  gas  or 
hydrogen  to  the  extent  of  from  about  16  to  26  per  cent.  (Professor 
V.  B.  Lewes.) 

Carburetted  water  gas  gives  a  small  flame  and  lower  durability 
than  coal  gas  of  equal  illuminating  power. 

Coal  gas  carburetted  by  petroleum  gives  larger  flame  and  higher 
durability. 

The  enriching  value  of  33-candle  carburetted  water  gas  is  from 
6  to  8  per  cent,  higher,  and  47-candle  carburetted  water  gas  is 
10  per  cent,  higher  than  when  tested  alone  in  the  photometer. 
(A.  Wilson.) 

Messrs.  Frankland  and  Wright,  and  Dr.  J.  Louttit  found  by 
experiments  with  young  rabbits  that  the  effects  of  carbonic  oxide 
were  not  more  poisonous  than  ordinary  coal  gas. 

Approximate  Cost  of  Water  Gas  per  1,000  Cubic  Feet  at  25 
Candles. 

*.   d. 

Oil,  4  gallons  at  3%d .         12 

45  Ibs.  coke  for  generator,  and  12  Ibs.  for  steam,  J      n     03 
equal  to  57  Ibs.  at  12*.  6d.  per  ton  .         .        .      ( 

Labour  03 

Purification 01 

Wear  and  tear 0    OJ 

1  10£ 

By  the  Van  Steenbergh  process  30  Ibs.  to  40  Ibs.  foundry  coke  are 
required  per  1000  cubic  feet  gas  made  and  carburetted  with  from 
3  to  3£  gallons  naptha.  Illuminating  power  equal  to  22  candles  ; 
loss  of  illuminating  power  by  storage  in  cold  weather,  2  candles. 
CO  equal  to  15  to  20  per  cent. 


400 


GAS  ENGINEER'S  POCKET-BOOK. 


Composition  and  Illuminating  Power  of  Gas  from  Van  Steenbergh 
Process,  with  Different  Fuels  and  76°  Naptha.     (V.  B.  Lewes.) 


Gas  Coke. 

Anthracite. 

Foundry 

Coke. 

Unpuri- 
lied. 

Purified. 

Unpuri- 
fied. 

Purified. 

H     . 

33-44 



39-05 



38-44 

Marsh  gas    .         .     . 

28-38 

— 

26-71 

— 

19-30 

Illumiuants 

11-14 



9-27 

— 

7-49 

CO       . 

19-00 



13-50 



23-81 

C0a          .         .         . 

2-24 

(i'Ol 

1-02 

2-16 

0-42 

N         .         .         .     . 

9-50 



9-72 

— 

9-69 

0     . 

1-30 



0-73 

— 

0-85 

H2S     . 
Illuminating   power 
corrected 

nil 
)    22-4 
j'  candles 

0-35 

nil 
22-9 
candles 

trace 

nil 
21.8 
candles. 

Manufacture  of  Dowsou  Producer  Gas. 

Superheated  steam  and  air  are  passed  through  a  generator  con- 
taining a  good  body  of  incandescent  fuel  (preferably  anthracite 
coal,  but  coke  will  do),  the  air  supporting  combustion  ;  the  steam  is 
decomposed,  the  0  combining  with  the  C  of  the  fuel,  first  making 
C02,  but  on  passing  through  the  remainder  of  the  hot  fuel  is  reduced 
to  CO,  which  is  necessary  to  ensure  that  it  has  a  sufficient  affinity  for 
0  to  explosively  combine  with  the  0  of  the  air  in  the  gas  engine 
cylinders,  while  it  must  be  remembered  that  each  molecule  of  C02 
makes  two  of  CO.  The  gases  are  led  through  coolers  and  condensers 
when  they  are  ready  for  use.  10  Ibs.  of  anthracite  yield  about  1,000 
cubic  feet  of  gas,  but  to  this  must  be  added  2  Ibs.  of  coke,  required  for 
the  steam  boiler. 

With  Dowson  gas  1  Ib.  of  fuel  per  I.H.P.,  or  1£  Ibs.  per  break 
horse-power  can  be  attained  in  a  gas  engine. 

Dowson  gas  is  about  equal  to  coal  gas  at  Is.  Qd.  per  1,000  cubic 
feet,  as  about  four  or  five  times  the  quantity  is  required,  and  larger 
engines  are  necessary. 

One  pound  steam  per  1  Ib.  Welsh  anthracite  is  usually  allowed  in 
Dowson  gas.  The  producer  must  be  kept  hot,  or  tarry  matters  will  be 
deposited. 

Dowson  water  gas  has  about  one  fourth  or  one  fifth  the  explosive 
force  of  coal  gas,  but  requires  for  its  production^  only  14  Ibs.  of 
anthracite  coal  per  1 ,000  cubic  feet. 

Dowson  producer  gas  contains  from  45  to  48  per  cent.  N. 

Siemens  producer  gas  generally  contains  60  to  70  per  cent.  N, 
which  renders  rapid  ignition  difficult. 


FUEL    GAS.  401 

Heating  value  of  Dowson  gas,  150  British  thermal  units  per  cubic 
foot.  Air  required  for  complete  combustion  of  Dowson  gas  equals  1  to 
1,  to  1J  to  1,  by  volume  of  the  gas.  With  Dowson  gas  the  products  of 
combustion  must  be  expelled. 

In  the  Dowson  producer  1  Ib.  of  steam  is  required  per  pound  of 
anthracite. 

Dowson  gas  requires  one  and  a  half  volumes  of  atmospheric  air  per 
volume  of  the  gas  for  complete  combustion. 

The  initial  pressure  in  gas  engines  is  more  than  double  that  usually 
adopted  in  steam  engines,  and  this  gives  the  gas  engine  an  advantage. 

A  steam  engine  cannot  convert  into  work  more  than  30  per  cent,  of 
the  heat  energy.  A  hot-air  engine  cannot  convert  into  work  more 
than  50  per  cent,  of  the  heat  energy.  An  internally  fired  gas  engine 
cannot  convert  into  work  more  than  80  per  cent,  of  the  heat  energy. 
(Professor  Kennedy.) 

Coke  for  use  in  Dowson  producers  should  be  clean  (not  mixed  with 
small  coal  or  yard  sweepings)  and  in  pieces  about  1  inch  to  1^  inches 
cube. 

About  80  cubic  feet  Dowson  gas  made  from  coke  are  required  per 
I.  H.  P.  per  hour. 

Gasholder  required  for  Dowson  gas  for  100  I.  H.  P.  plant  is  8  feet 
diameter  X  8  feet  deep  ;  contents  400  cubic  feet. 

Dowson  gas  has  about  one-fourth  the  explosive  force  of  ordinary 
coal  gas. 

The  generator  gas  contains  a  large  proportion  of  nitrogen  and  some 
C02. 

CO  does  not  ignite  as  rapidly  as  H. 

It  is  necessary  to  use  a  higher  compression  for  a  charge  of  generator 
gas  than  for  ordinary  town  gas,  so  as  to  bring  the  molecules  together. 

The  volume  of  exhaust  steam  and  products  of  combustion  in  a 
steam  power  plant  is  reduced  90  per  cent,  when  gas  power  is  used. 

If  coal  gas  be  subjected  to  sudden  and  severe  refrigeration  it  will 
part  with  some  of  its  valuable  hydrocarbons,  and  this  to  a  greater 
extent  if  the  gas  be  stagnant. 

Nineteen  to  twenty  candle  gas,  which  has  been  purified  by  2£  per 
cent,  air,  does  not  lose  any  appreciable  quantity  of  illuminating 
power  during  a  travel  of  eight  or  nine  miles  through  the  town  mains. 


Fuel  Gas. 

Semi-water  gas  contains  from  80  to  85  per  cent,  of  the  heating 
value  of  coal,  and  is  the  cheapest  gas  if  supplied  within  a  reasonable 
distance  from  the  place  of  production. 

The  producer  consists  essentially  of  a  cylindrical  shell  of  boiler- 
plate lined  with  fire  brick.  The  internal  diameter  of  the  brick- 
work is  21  inches  and  the  height  from  the  grate  to  the  top  of  the 
furnace  is  3£  feet.  The  grate  is  connected  at  one  side  with  a  steam 
and  air  injector,  and  on  the  other  side  with  a  gas  supply-pipe.  It 
is  surrounded  by  a  cast  iron  ashpit,  A  small  reservoir  or  boiler  is 
placed  at  one  side,  connected  with  which  are  two  coils  contained  in 

«.£.  D  D 


402  GAS  ENGINEER'S  POCKET-BOOK. 

the  brickwork,  the  lower  of  which  supplies  steam  and  the  upper  one 
of  which  superheats  it.  Air  channels  are  formed  in  the  brickwork, 
arranged  spirally,  through  which  air  is  drawn  by  the  injector  and 
heated  before  mixing  with  the  steam.  The  grate  is  provided  with 
mechanism  giving  it  a  rotary  and  up-and-down  movement  to  break 
up  clinker  or  caking  soft-coal.  Five  hundred  cubic  feet  of  gas  per 
hour  can  be  produced  from  6  Ibs.  or  7  Ibs.  of  coal.  (A.  Kitson.) 

Peebles  Process. 

The  retorts  used  in  the  Peebles  process  yield  500  cubic  feet  of  gas 
per  hour,  and  5£  cwts.  (per  ton  of  oil  decomposed)  of  hard  graphite 
coke. 

Heat  required  for  fresh  oil  in  Peebles  process  retorts  equals  1,100 
to  1,200°  F.  For  condensible  products,  1,400  F. 

Oil  of  '850  specific  gravity  gave  5  cwt.  coke  per  ton  at  Perth. 

Enriching  value  of  Peebles  oil  gas  is  50  per  cent,  higher  than  the 
illuminating  power  when  burnt  alone.  (S.  Glover.) 

Peebles  oil  gas  used  as  an  enricher  has  prevented  the  stoppage  of 
services  with  napthalene  during  the  most  severe  winter. 

One  ton  of  tar  from  Durham  coal  by  the  Peebles  process  yields 
15,000  cubic  feet  of  25  candle  gas,  and  15  cwt.  coke  of  good  quality. 
(Bell.) 

Dr.  Stevenson  Macadam  stated  (1887)  that  he  considered  6,885  Ibs. 
of  sperm  light  as  the  theoretic  value  of  the  gas  from  1  ton  of  oil. 

He  found  mixing  oil,  gas,  and  air  entailed  a  loss  of  illuminating 
power  ;  after  making  all  allowance  for  the  admixture,  he  advocated  the 
use  of  water  gas  as  a  diluent  for  oil  gas. 

To  gasify  tar  permanently  about  2,000°  F.  is  required. 

It  has  been  suggested  when  supply  of  gas  is  short  to  mix  about  2 
gallons  of  tar  per  charge  with  the  coals,  and  thus  keep  up  the 
illuminating  power. 

Oases  passed  over  Gasolene  at  50°  F.  will  completely  evaporate  it, 
giving  air  an  illuminating  power  of  60  candles,  and  poor  gas  an 
illuminating  power  of  80  candles. 

No  condensation  has  been  found  in  the  syphon  boxes  in  the  district 
in  Kochdale,  when  carburine  has  been  used  as  an  enricher. 

It  is  best  when  enriching  with  a  cold  process  to  put  the  enriching 
apparatus  on  the  delivery  pipe  from  the  works. 

One  Gallon  Carburine  (specific  gravity  0'680)  will  raise  8,000  cubic 
feet  1  candle. 

Yield  of  Gas  in  Pintsch  System  equals  81  to  83  cubic  feet  per  gallon  of 
51  candles  ;  compression  to  150  Ibs.  per  square  inch,  reduces  illuminat- 
ing power  to  38  candles,  and  deposits  one  gallon  hydrocarbon  per 
1,000  cubic  feet.  (J.  Tomlinson.) 

Cost  of  fitting  gas  to  railway  carriages  (Pintsch  or  Pope  systems) 
equals  about  £5  per  lamp,  including  its  proportion  of  reservoirs,  pipes, 
gauges,  &c.  Cost  of  working  about  ^ths  of  a  penny  per  lamp  per 
hour  equals  about  one-half  that  of  oil.  Maintenance  costs  about  2*. 
per  lamp  per  year. 


COMPRESSING    COAL    GAS. 


403 


Loss  in  Volume  of  Coal  Gas  when  Compressed.    (C.  E.  Botley.) 
Illuminating  power  of  gas  16-50  candles. 


Pressure. 

Volume. 

Loss. 

Lbs. 
per  Square 
Inch. 

Atmo- 
spheres. 

Gas  put 
into 
Cylinder. 

Gas 

used  per 
Meter. 

CuMc 
Feet. 

Per  Cent. 

45 

3 

510 

510 

nil. 

nil. 

75 

5 

850 

860 

10 

1-16 

105 

7 

1,190 

1,205 

15 

1-24 

135 

9 

1,530 

1,570 

40 

2-54 

1G5 

11 

1,870 

1,920 

50 

2-60 

195 

13 

2,210 

2,330 

120 

5-15 

200 

1*1 

2,267 

2,450 

183 

7-47 

Notes  on  Suction  Gas  Producers. 

The  gases  made  are  said  to  be  very  equal  in  quality  and  character. 

The  producer  should  be  stoked  every  2  or  3  hours,  but  can  be  left 
for  5  or  6  hours  if  necessary.  If  closed  down  for  a  week  they  will 
probably  be  found  alight. 

Larger  valves  are  required  in  the  engines  than  for  town's  gas. 

The  gas  comes  off  in  from  15  to  20  minutes  after  starting  with  all 
cold. 

Magneto  ignition  is  necessary. 


H    . 
CH4 
CO  . 
N 
C03. 


Average  Composition  of  Suction  Gas. 

.     57-41  B.T.U. 
19-17 


17-6  per  cent. 
1-6 


18-6 

54-4 

7-2 

99-4 


60-17 


136-75 


r>  D  2 


404  GAS  ENGINEER'S  POCKET-BOOK. 


PRODUCTS   WORKS. 

Chimneys  in  chemical  works  should  be  at  least  250  feet  high. 

The  simplest  form  of  sulphate  plant  is  a  boiler  in  which  the  liquor 
is  heated,  and  from  which  a  pipe  to  convey  the  vapours  is  carried 
to  the  sulphuric  acid  in  the  saturator  where  sulphate  crystals  are 
formed.  The  addition  of  lime  or  caustic  soda  to  the  liquor  in  the 
boiler  causes  the  ammonia,  combined  with  other  gases  which  are  in 
the  liquid,  to  pass  off  as  gas,  and  consequently  be  converted  into 
sulphate. 

Seventeen  parts  pure  ammonia  combine  with  49  parts  pure 
sulphuric  acid  to  form  66  parts  sulphate  of  ammonia  (2  (NHJ  SOJ. 


Reaction  of  Ammonia cal  Liquor  and  Sulphuric  Acid. 
2  NH3  +  H2  SO,  =  2  (NHJ  S04. 

The  volatilization  of  the  ammonia  from  gas  liquor  in  all  modern 
plant  is  effected  by  means  of  continuous  working  stills,  viz.,  distilling 
a  regular  stream  of  liquor  as  it  flows  by  its  own  gravity  through  the 
intricacies  of  a  still  heated  by  direct  steam. 


To  calculate  amount  of  Sulphate  of  Ammonium  to  be  obtained 
from  Liquor. 

Ounce  strength  X  1'347  X  gallons  of  liquor  equals  ounces  weight 
of  sulphate ;  or,  ounce  strength  X  '0841  equals  Ibs.  sulphate  per 
gallon. 

2,000  gallons  of  8-ounce  liquor  will  produce  15  cwt.  sulphate, 
requiring  also  13  J  cwt.  of  sulphuric  acid,  or,  say,  1  ton  sulphate  per 
100  tons  of  coal  in  small  works. 

One  per  cent.  N  in  coal  equals  105  Ibs.  ammonium  sulphate  (pure). 
(Butterfield.) 

Coal  may  be  said  to  contain  1J  per  cent.  N  equal  to  140  Ibs. 
sulphate  of  ammonia  per  ton  ;  it  is  not  usual  to  obtain  more  than 
27  or  28  Ibs.  sulphate. 

In  sulphate  plant  it  is  necessary  that  the  condensers  and  purifiers 
be  of  ample  capacity. 

Mr.  Croll  proposed  to  make  sulphate  of  ammonia  by  passing  the 
products  of  combustion  from  a  coke  furnace  through  a  "  coffey  "  still 
containing  ammoniacal  liquor,  and  then  precipitating  the  sulphate  in 
the  usual  saturator.  He  thus  obtained  an  increase  of  sulphate  per 
gallon  of  acid,  and  greatly  lessened  the  quantity  of  H2S  given  off. 

Of  the  1-7  per  cent,  of  N  in  the  coal,  only  about  -25  per  cent, 
appears  as  ammonia  after  carbonization.  Some  coals  contain  as  much 
as  2  per  cent.  N.  If  all  the  N  were  converted  into  NH8,  sulphate  would 
equal  215  Ibs.  per  ton  of  coal.  About  50  per  cent,  of  the  N  remains 
in  the  coke.  About  '027  per  cent,  of  the  N  in  the  coal  forms  in  the 


SULPHATE    MANUFACTURE.  405 

purifiers  calcium  cyanide  and  calcium  cyanate.  If  steam,  water  gas 
or  hydrogen  were  passed  through  heated  coke,  a  large  proportion  of 
the  N  could  be  removed,  and  afterwards  converted,  and  with  that 
already  evolved  with  the  gas  a  make  of  about  1  cwt.  of  sulphate  per 
ton  could  be  obtained. 

One  ton  sulphate  equals  about  5  cwt.  NH.a 

One  ton  10-ounce  liquor  equals  about  51  Ibs.  NH3  equals  2£  per  cent. 

One  ton  sulphate  equals  11  tons  10-ounce  liquor. 

One  ton  coal  produces  35  to  40  gallons  10-ounce  liquor  equal  to  30 
to  35  Ibs.  sulphate. 

7,000  gallons  liquor  require — 

Yield  as  Compared 

with  Theory. 
Hours.       Per  Cent. 

When  heated  by  open  fire  from  without     .        .  22  90'0 

When  heated  by  a  steam  coil  (indirect  steam)  .18      .      92*0 
When  open  steam  is  blown  in     .        .        .        .  14  98*5 

(Dr.  Lunge.) 

The  liquor  in  the  saturator  should  be  kept  about  54°  Twaddell. 

Efficient  sulphate  plant  requires  about  8  cwt.  fuel  per  ton  sulphate 
made. 

Temperature  in  sulphate  well  equals  75°,  after  passing  jet  elevator 
116°. 

In  the  economiser  180°.     (S.  Ellery.) 

The  waste  gases  from  the  saturator  have  usually  a  temperature  of 
186°  F.,  and  by  utilizing  these  the  liquor  can  be  raised  to  about 
113°  F. 

According  to  the  reports  of  the  Chief  Inspector  under  the  Alkali 
Works  Regulation  Act,  the  make  of  sulphate  of  ammonia  was— 

For  1894.  Tons. 

In  Gasworks .  110,748 

„  Ironworks    . 11,000 

„  Shale  works 23,105 

„  Coke  and  Carbonizing  Works      .        .    .  4,973 

Totals         .        .        149,826 

To  manufacture  sulphuric  acid,  burn  S,  and  pass  with  peroxide  of 
nitrogen,  air  and  steam,  in  regulated  quantities  to  a  large  chamber, 
where  H2S04  condenses,  and  is  of  sufficient  strength  for  the  manu- 
facture of  sulphate  (equation  2  S02  +  N04  +  2  H20  =  2  H2S04  + 
NO,). 

Sulphate  of  ammonia  contains  20  per  cent,  of  nitrogen,  and  nitrate 
of  soda  only  15  per  cent.  Three-quarters  of  a  ton  of  sulphate  has  in 
it  as  much  food  for  a  crop  as  a  ton  of  nitrate.  Of  course  it  is  true 
that  the  nitrogen  in  the  nitrate  is  accepted  as  being  more  effective 
than  the  nitrogen  in  the  sulphate,  but  the  outside  difference  in 
manurial  power  is  certainly  not  more  than  10  per  cent. 


406 


GAS  ENGINEER'S  POCKET-BOOK. 


When  it  is  also  remembered  that  the  more  concentrated  nature  of 
sulphate  means  a  saving  of  25  per  cent,  on  the  carriage,  and  that  it 
can  often  be  bought  at  still  lower  rates  from  local  gasworks,  it  is 
clear  that  for  any  other  than  very  light  sandy  soils,  sulphate  rather 
than  nitrate  should  be  bought  at  present. 

Professor  Somerville  states  that  sulphate  of  ammonia  and  nitrate 
of  soda  are  nearly  of  equal  value  per  unit  of  nitrogen  as  manures, 
therefore  861bs.  sulphate  equals  112  Ibs.  nitrate. 

Sulphate  of  ammonia  has  proved  itself  a  better  nitrogenous  manure 
for  mangolds  than  nitrate  of  soda. 

One-eighth  cwt.  sulphate  of  ammonia  per  acre  on  hay  land  is  the 
best  dressing ;  or  f  cwt.  sulphate  equals  1  cwt.  nitrate  of  soda. 

Preliminary  nitrification  of  sulphate  of  ammonia  is  not  necessary 
when  using  the  latter  as  a  manure. 

From  Coal  Tar  are  obtained  by  distillation  the  following  valuable 
bodies  :  benzene,  toluene,  naptha,  carbolic  acid,  creosote,  anthracene, 
napthalene,  and  a  residue  of  pitch.  The  benzene  and  toluene  yield 
aniline  whence  the  dyes  magenta  and  methyl  violet  are  obtained  ;  the 
phenol  and  creosote  form  the  basis  of  valuable  antiseptic  and  dis- 
infectant preparations,  and  the  first-named  is  also  the  source  of  the 
dye  aurine  ;  naptha  is  valuable  chiefly  as  a  rubber  solvent ;  naptha- 
lene yields  napthylamine,  abeta-napthol,  vermillene,  scarlet,  and 
napthol  yellow  ;  anthracene  gives  on  treatment  alizarin,  from  which  a 
great  number  of  beautiful  dyes  are  prepared.  By  itself,  also,  coal  tar 
has  many  applications,  as,  for  instance,  for  making  gas  as  fuel,  and 
as  a  preservative  for  building  materials.  Then  should  be  mentioned 
the  legion  of  coal  tar  derivatives  :  antipyrin,  antifebrin,  analgen, 
exalgine^  salol,  saccharin,  and  salicylic  acid.  (Lancet.) 

Constituents  of  Coal  Tar. 


Average 

Weight 
Per 

Proportionate  Weight 
of  Constituents. 

Calorific  Value. 

Cent. 

C. 

H. 

C. 

H. 

Units. 

Units. 

First  runnings 

C6H10 

3 

•025714 

•004286 

200 

148 

Light  oil    .    . 

CgHu 

7 

•061091 

•008910 

474 

307 

Middle  oils 

Ci2H<jo 

27 

•237073 

•032927 

1,842 

1,145 

Heavy  oils  .     . 

C;uH16 

7 

•063913 

•006087 

497 

210 

Pitch   (56  per 

cent.)    com- 

posed of  Oils 

CieHio 

17-5 

•166336 

•008663 

1,292 

298 

Carbon  .     .    . 

C 

27-5 

•275000 

— 

2,137 

Gases    and 

Water  (H, 

NH.).     .     . 

— 

11 

- 

•829127 

•060873 

6,442 

2,108 

Total     .... 

0-89 

8,550 

ANALYSES     OF     TAB. 


407 


The  number  of  constituents  taken  was  :  First  runnings,  17  ;  light 
oil,  26  ;  middle  oils,  5  ;  heavy  oils,  15  ;  and  pitch  oils,  4. 

The  boiling  points  were  respectively  :  Up  to  110°  C.  ;  110°  to  210°  C. ; 
210°  to  240°  C.  ;  240°  to  270°  C.  and  upwards ;  and  360°  C.  and 
upwards.  (F.  G.  Dexter.) 

Average  yield  of  tar  per  ton  of  coal  equals  1  cwt.  equal  to  10  gallons. 

When  tar  is  distilled  the  first  portion  volatilized  is  principally  NH3 
and  some  gases  suspended  in  the  hydrocarbons,  then  ammoniacal 
liquor  and  a  small  quantity  of  brown  oil,  or  naptha,  or  "  light  "  oil,  of 
which  from  5  to  20  per  cent,  is  contained  in  the  tar.  At  a  higher 
heat  first  some  almost  colourless  light  oils  come  over,  and  then  an 
olive  or  greenish  heavy  oiJ  ("  dead  oil "),  next  a  greenish  yellow  fluid 
which  becomes  almost  like  butter.  The  contents  of  the  retort  consist 
of  pitch. 


Besnlts  of  Distillation  of  Tar.     (Professor  Wanklyn.) 


Ammoniacal  liquor 
First  light  oils 
Second      „ 


Per 
Cent. 
4-0 
1-5 
1-5 


Creosote  oils 
Anthracene  oils 
Pitch 


Per 
Cent. 
22-0 

4-0 
67-0 


Composition  of  Tar  (London).     (Professor  Lewes.) 


C 
H. 

N 


Per 
Cent. 
77-53 
6-33 
1-03 


Per 

Cent 

0-61 

14-50 


Analysis  of  Tar  from  Caking  Coal  at  Different  Temperatures, 
(L.  T.  Wright.) 


Yield  of  Gas 
Per  Ton. 

Specific 
Gravity  of 
Tar. 

Pitch. 

Light 
Naptha. 

Cubic  Feet. 

Per  Cent. 

Per  Cent. 

6,600 

•086 

29-89 

7,200 

•120 

— 

9 

8,900 

•140 

10,160 

•154 

— 

3 

11,700 

•206 

64-08 

1 

Average  Analysis  of  Tar. 

London.  Country. 

Ammoniacal  water        ....      4'7  per  cent.      4  per  cent. 

Total  light  oils 2-4        „  3        „ 

Carbolic  and  creosote  oils     .         .         .     20'3        „  22        „ 

Anthracene  oils 13'0        „  4         „ 

Pitch  (grams  per  100  cubic  centimetres,   59*6        „  67        „ 


408        GAS  ENGINEER'S  POCKET-BOOK. 


Average  Percentage  of  Products  from  Ordinary  Tar. 

Ammoniacal  liquor,  gases  and  loss       .        .  9'2  per  cent. 

Light  oils 1-4.       „ 

Second  light  oils 1'6       „ 

Creosote  oils 2O5       „ 

Anthracene  oils 6'9       „ 

Pitch 60-4       „ 

The  expression  "  light  oils  "  means  those  oils  which  are  lighter  than 
water. 


Distillation  of  tar  (extreme  case)  average  difficult  to  obtain. 


Result  of  Distillation  of  1,200  Gallons  Tar. 

Lancashire.  London. 

Ammoniacal  liquor      .         .         .30  gallons.     50  gallons. 
First  light  oils        .        .         .     .     33       „  20      „ 

Second  light  oils         .        .         .157       „  20      „ 

Creosote  oils 104      „  250      „ 

Anthracene  oils            .        .        .  229      „  50      „ 

Pitch 3£  tons.          4  tons. 


Analysis  of  Coal  Tar.     (E.  J.  Mills.) 

Scotch 

Constituents.                                         London.  Cannel. 

Carbon 77'53        .  85-33 

Hydrogen 6'33        .  7-33 

Nitrogen 1-03        .  0'85 

Sulphur 0'61        .  0-43 

Oxygen 14'50        .  6'06 


Tar  from  a  gasworks  where  Boghead  cannel  was  used  gave  the 
following  results  : — 

Water,  ammonia,  salts,  &c 6-0  per  cent. 

Light  oil 16-5        „ 

Heavy  oil 30-0        „ 

Pitch 41-5        „ 

Permanent  gases 5-0        „ 

The  quantity  of  tar  increases  with  the  percentage  of  O  in  the  coal. 
(Dr.  Biinte.) 


ANALYSES    OF    COAL    TAR.  409 

Products  from  Distillation  of  Lancashire  Coal  Tar. 
1,000  gallons  Tar,  1-16  specific  gravity  equals  5'3  tons. 

Per  1,000  Percentage 

Gallons.  by  Weight.         Per  Ton. 

a.  Ammonia  liquor,  4  ozs.      .       25  gallons  =  2*2  4f  gallons. 

b.  First  light  oils  .        .  28       „  =    2-2  5£        „ 

c.  Second  light  oils  .        .     .     131       „  =  10'6  24f       „ 

d.  Creosote  oils      .        .  87      „  =    7-6  16 J        „ 

e.  Anthracene  oils    .        .     .    191      „  =  16-9  36 
/.Pitch 3£tons  =  60'5  12£  cwts, 

On  further  rectification,  these  distillates  yield — 

b.  90  per  cent,  benzol      ....  about  6  gallons. 

c.  Solvent  naptha ,,    74      „ 

d.  Carbolic  acid »      6£     „ 

e.  30  per  cent,  anthracene  ....  „    -50  cwt. 
Equal  to  pure  anthracene  .         .        .  „    '15    „ 

Specific  gravity  of  coal  tar     .        .  =    1-12  to  1-16. 
Specific  gravity  of  cannel  coal  tar  =      '98  to  T06. 
1  gallon  tar  at  1*16  specific  gravity  =  11 '6  Ibs. 
1  cubic  foot  tar    „        „  „        =  72-5  Ibs. 

Analysis  of  Coal  Tar,     (A.  Colson.) 

Coal  used,  Derbyshire,  18  per  cent. ;  Nottingham  cannel  (producing 

10,436  cubic  feet  of  17-candle  gas),  9  per  cent. ;  Yorkshire,  73  per 
cent.  : — 

Crude  naptha,  30  per  cent,  at  120°  C.  .        .  6'79  gallons. 

Carbolic  acid,  crude,  60° 1-14        „ 

Heavy  naptha,  20  per  cent,  at  160°  C.          .  3-55        „ 

Creosote 58'04        „ 

Ammoniacal  liquor,  10  ozs 5'00        „ 

Napthalene 33-91  Ibs. 

Anthracene,  33  per  cent.          .        .        .     .  13*60    „ 

Pitch 12-67    „ 

Products  from  One  Ton  of*  Tar  (1886).    (J.  T.  Lewis.) 

Benzol  (50/90)         ....  5  gallons. 

Naptha 2       „ 

Carbolic  acid 5      ,, 

Creosote  oil 50       „ 

Anthracene 30  Ibs.  of  35  per  cent. 

Napthalene 2  cwts. 

Pitch 11     „ 

Tar  from  Newcastle  coals  contains  much  napthalene  and  anthracene. 
Tar  from  Wigan  coals  contains  much  benzol  and  phenol.  (Hornby.) 
Aniline  (C12H7N)  is  obtained  from  the  heavy  tar  oils  by  agitation 

with  hydrochloric  acid,  and  decomposed  by  a  slight  excess  of  potash 

or  soda  and  twice  distilled. 


410        GAS  ENGINEER'S  POCKET-BOOK. 


STATUTORY  AND  OFFICIAL  REGULATIONS  FOE  TESTING  THE 
ILLUMINATING   POWER  AND   PURITY  OF   GAS. 

Extract  from  the  Gasworks  Clauses  Act,  1871. 

SECTION  28. 

The  undertakers  shall  cause  to  be  provided,  at  the  place  prescribed 
and  within  the  prescribed  time,  a  testing  place,  with  apparatus  therein, 
for  the  purposes  following,  or  such  of  them  as  may  be  prescribed  by 
the  special  Act,  that  is  to  say  : — 

1.  For  testing  the  illuminating  power  of  the  gas  supplied. 

2.  For  testing  the  presence  of  sulphuretted  hydrogen  in  the  gas 

supplied. 

The  said  apparatus  shall  be  in  accordance  with  the  regulations  pre- 
scribed in  Part  I.  of  the  Schedule  A.  to  this  Act  annexed,  or  according 
to  such  rules  as  may  from  time  to  time  be  substituted  in  lieu  thereof 
by  any  special  Act,  and  shall  be  so  situated  and  arranged  as  to  be  used 
for  the  purpose  of  testing  the  illuminating  power  and  purity  of  the 
gas  supplied  by  the  undertakers,  and  the  undertakers  shall  at  all 
times  thereafter  keep  and  maintain  such  testing  place  and  apparatus 
in  good  repair  and  working  order. 


SCHEDULE  A.  PAST  I. 
Regulations  in  respect  of  Testing  Apparatus. 

1.  The  apparatus  for  testing  tke  illuminating  power  of  the  gas 
shall  consist  of  the  improved  form  of  Bunsen's  photometer,  known 
as  Letheby's  open  60-inch  photometer,  or  Evans'  enclosed  100-inch 
photometer,  together  with  a  proper  meter,  minute  clock,  governor, 
pressure  gauge  and  balance. 

The  burner  to  be  used  for  testing  the  gas  shall  be  such  as  shall  be 
prescribed. 

The  candles  used  for  testing  the  gas  shall  be  sperm  candles  of  six 
to  the  pound,  and  two  candles  shall  be  used  together. 

2.  The  apparatus — (a)  for  testing  the  presence  in  the  gas  of  sul- 
phuretted hydrogen. — A  glass  vessel  containing  a  strip  of  bibulous 
paper  moistened  with  a  solution  of  acetate  of  lead  containing  60  grains 
of  crystallized  acetate  of  lead  dissolved  in  one  fluid  ounce  of  water. 


SCHEDULE  A.  PART  II. 
1.  Mode  of  Testing  for  Illuminating  Power. 

The  gas  in  the  photometer  is  to  be  lighted  at  least  fifteen  minutes 
before  the  testings  begin,  and  it  is  to  be  kept  continuously  burning 
from  the  beginning  to  the  end  of  the  tests. 

"teach  testing  shall  include  ten  observations  of  the  photometer,  made 
at  intervals  of  a  minute. 


ILLUMINATING   POWER   AND   PURITY   OF   GAS.  411 

The  consumption  of  the  gas  is  to  be  carefully  adjusted  to  5  cubic 
feet  per  hour. 

The  candles  are  to  be  lighted  at  least  ten  minutes  before  beginning 
each  testing,  so  as  to  arrive  at  their  normal  rate  of  burning,  which 
is  shown  when  the  wick  is  slightly  bent  and  the  tip  glowing.  The 
standard  rate  of  consumption  for  the  candles  shall  be  1 20  grains  each 
per  hour.  Before  and  after  making  each  set  of  ten  observations  of 
the  photometer,  the  Gas  Examiner  shall  weigh  the  candles,  and  if  the 
combustion  shall  have  been  more  or  less  per  candle  than  120  grains  per 
hour,  he  shall  make  and  record  tha  calculations  requisite  to  neutralise 
the  effects  of  this  difference. 

The  average  of  each  set  of  ten  observations  is  to  be  taken  as  repre- 
senting the  illuminating  power  of  that  testing. 

2.  Mode  of  Testing  foi*  Sulphuretted  Hydrogen. 

The  gas  shall  be  passed  through  the  glass  vessel  containing  the 
strip  of  bibulous  paper  moistened  with,  the  solution  of  the  acetat<f 
of  lead  for  a  period  of  three  minutes,  or  such  longer  period  as  may 
be  prescribed  ;  and  if  any  discolouration  of  the  test  paper  is  found  to 
have  taken  place,  this  is  to  be  held  conclusive  as  to  the  presence  of 
sulphuretted  hydrogen  in  the  gas. 


Extract  from  Memorandum  issued  by  the  Standards  Department  of 
the  Board  of  Trade  (July  1st,  1891),  requiring  Photometers  to 
be  verified  and  stamped. 

Where  the  photometer,  or  apparatus  for  testing  the  illuminating 
power  of  gas,  consists  of  the  improved  form  of  Bunsen's  photometer, 
known  as  Letheby's  open  60-inch  photometer,  or  Evans'  enclosed 
100-inch  photometer,  then  the  official  verification  will,  in  accordance 
with  established  practice,  include  the  burner,  meter,  minute  clock, 
scale,  governor,  pressure  gauge,  and  other  subsidiary  measuring  instru- 
ments. A  certificate  of  verification  is,  however,  only  issued  if  such 
photometers  are  of  the  Evans  or  Letheby  forms  hitherto  recognised  by 
the  Department. — [The  Board  now  also  certify  the  table  photometer.] 


Directions  for  Using  Standard  Sperm  Candles. 

Cut  a  candle  into  halves,  cut  round  half  an  inch  from  the  new  end 
of  each  piece,  care  being  taken  not  to  cut  the  wick,  and  slip  off  the 
small  piece  of  spermaceti ;  light  the  wicks  and  let  them  burn  for  about 
five  minutes  ;  see  if  the  wicks  are  central.  If  they  are,  let  them  burn 
for  about  twenty  minutes,  till  they  are  in  proper  burning  order,  before 
commencing  experiment. 

When  it  is  desired  to  extinguish  the  candles,  touch  the  wicks  first 
with  a  piece  of  spermaceti. 

The  caudles  should  be  kept  in  a  cool  place,  in  a  proper  tin  candle- 
box. 


412  GAS  ENGINEER'S  POCKET-BOOK. 

NOTIFICATION  OF  THE  GAS  REFEREES  FOR  THE  YEAR  1906. 

KEVISED  AUGUST,  1906. 

As  to  the  Service  Pipes  to  the  Testing  Places. 

The  conditions  to  be  observed  in  connecting  the  Gas  Companies' 
mains  with  the  apparatus  in  the  testing  places  and  in  providing  for 
shutting  off  the  gas  in  case  of  emergency  are  prescribed  by  section  8 
of  the  London  Gas  Act,  1905. 

If  obstruction  of  the  service  pipe  is  found,  or  if  there  is  reason  to 
think  that  the  quality  of  the  gas  is  suffering  from  any  change  occur- 
ring within  the  service  pipe,  the  service  pipe  may  be  washed  out  in 
the  presence  of  and  by  arrangement  with  the  Gas  Examiner,  either 
with  hot  water  alone  or  with  any  usual  solvent  such  as  benzol, 
naphtha,  or  petroleum,  but  the  use  of  such  solvents  is  to  be  followed  by 
a  washing  with  hot  water.  In  every  case  where  the  service  pipe  is 
washed  out  the  gas  company  shall  send  a  letter  to  the  Gas  Referees 
explaining  why  the  washing  was  considered  necessary.  The  gas 
companies  may,  if  they  think  fit,  provide  a  tap  and  funnel  in  any 
testing  place  for  the  purpose  of  such  washing  out. 

No  testing  for  illuminating  power  is  to  be  made  until  after  the  lapse 
of  an  hour  since  the  last  washing  out. 

As  to  the  Standard  Lamp  to  be  used  for  Testing  Illuminating  Power. 

The  standard  to  be  used  in  testing  the  illuminating  power  of  gas 
shall  be  a  pentane  10-candle  lamp  which  has  been  examined  and 
certified  by  the  Gas  Referees.  A  description  of  the  lamp  is  given  in 
Appendix  A.  The  residue  of  pentane  in  the  saturator  shall,  at  least 
once  in  each  calendar  month,  be  removed,  and  shall  not  be  used  again 
in  any  testings. 

The  pentane  to  be  used  in  this  lamp  shall  be  prepared  as  described 
in  Appendix  B.,  and  shall  show  when  tested  the  properties  there 
specified. 

All  pentane  provided  by  the  gas  companies  will  be  examined  and 
certified  by  the  Gas  Referees,  and  will  be  sent  to  the  testing  places  in 
cans,  which  have  been  both  sealed  and  labelled  by  them  ;  and  no 
pentane  shall  be  used  in  the  testing  places  other  than  that  which  has 
been  thus  certified. 

The  procedure  to  be  followed  in  the  issue  of  pentane  to  the  testing 
places  is  described  in  Appendix  C. 

As  to  the  Times  and  Mode  of  Testing  for  Illuminating  Power. 
I. — TESTING  WITH  THE  METROPOLITAN  ARGAND  BURNER,  No.  2. 
The  testings  for  illuminating   power   ma,de  with  the    Standard 
Argand  shall  be  three  in  number  daily.     "  Tne  tests  for  illuminating 
power  shall  be  taken  at  intervals  of  not  less  than  one  hour." 
average  of  all  the  testings  at  any  testing  place  on  each  day  of  the 
iUirniinating  power  of  the  gas  supplied  by  the  company  at  sucli  test- 
ing place  shall  be  deemed  to  represent  the  illuminating  power  of  such 
gas  on  that  day  at  such  testing  place."     (Gaslight  and  Coke  and 


ILLUMINATING  POWER  AND  PURITY  OP  GAS.  413 

other  Gas  Companies  Acts  Amendment  i  Act,  1880,  sections  7 
and  8.) 

But  "  if  on  any  one  day  the  gas  supplied  by  the  Company  at  any 
testing  place  is  of.  less  illuminating  power  to  an  extent  not  exceeding 
one  candle  than  it  ought  to  be,  the  average  of  all  the  testings  made  at 
such  testing  place  on  that  day  and  on  the  preceding  day  and  on  the 
following  day  shall  be  deemed  to  represent  the  illuminating  power  of 
the  gas  on  such  one  day  at  such  testing  place."  (London  Gas  Act, 
1905,  section  4  (3).) 

The  photometer  to  be  used  in  the  testing  places  shall  be  the  table 
photometer  described  in  Appendix  D.  The  air-gas  in  the  lamp  is  to 
be  kept  burning  so  that  the  flame  is  near  its  proper  height  for  at  least 
ten  minutes  before  any  testing  is  made.  At  the  completion  of  every 
testing  the  air-gas  is  to  be  turned  off ;  but  if  the  interval  between 
two  testings  does  not  much  exceed  one  hour  and  the  Gas  Examiner  is 
present  during  the  interval,  he  may,  instead  of  turning  it  off  completely, 
turn  it  down  low. 

The  Argand  burner  attached  to  each  photometer  shall  be  ;i  standard 
burner  called  the  Metropolitan  Argand  Burner,  No.  2,  which  has  been 
devised  by  Mr.  Charles  Carpenter.  A  description  of  the  burner  is 
given  in  Appendix  E.  No  Argand  burner  shall  be  used  for  testing 
the  illuminating  power  of  gas  that  does  not  bear  the  lead  seal  of  the 
Gas  Keferees. 

A  clean  chimney  is  to  be  placed  on  the  burner  before  each  testing, 
r.nd  care  should  be  taken  that  the  glass  does  not  become  dimmed  by 
i  3  smoking  of  the  flame. 

The  gas  under  examination  is  to  be  kept  burning,  at  about  the  usual 
rate,  for  at  least  fifteen  minutes  before  any  testin-  is  made  ;  the 
damper  shall  be  kept  down  during  this  interval.  No  gas  shall 
pass  thiough  the  meter  attached  to  the  photometer  except  that 
which  is  consumed  in  testing  or  during  the  intervals  between  the 
testings  made  on  any  day,  and  that  which  is  used  in  proving  the 
meter. 

The  paper  used  in  the  photoped  of  the  photometer  shall  be  white 
in  colour,  unglazed,  of  fine  grain  and  free  from  water  marks.  It  shall 
be  as  translucent  as  is  possible  consistently  with  its  being  sufficiently 
opaque  to  prevent  any  change  in  the  apparent  relative  brightnesc  of 
the  two  portions  of  the  illuminated  surface,  when  the  head  is  moved 
to  either  side.  This  paper  should,  when  not  in  use,  be  covered  tt 
protect  it  from  dust ;  and  if  it  has  been  in  any  way  marked  or  soiled 
a  fresh  piece  is  to  be  substituted. 

Each  testing  shall  be  made  as  follows  : — 

The  index  of  the  regulating  tap  shall  be  so  adjusted  that  the  meter 
hand  makes  one  complete  revolution  in  not  less  than  59  or  more  than 
61  seconds.  The  damper  for  regulating  the  air-supply  to  the  bui'ne* 
shall  be  screwed  upwards  until  the  flame  is  on  the  point  of  tailing 
above  the  chimney  and  then  immediately  be  turned  down  only  so  far 
as  to  ensure  that  the  flame  burns  and  without  any  smoking.  Thv 
connecting  rod  shall  now  be  pushed  to  and  fro  by  the  Gas  Examiner 
until  the  illumination  of  the  photoped  by  the  two  sources  of  light  is 
judged  to  be  equal.  A  balance  is  best  attained  by  making  small 


414        GAS  ENGINEER'S  POCKET-BOOK. 

alternations  of  decreasing  amplitude  rather  than  by  a  very  slow  move- 
ment in  one  direction  only.  The  reading  on  the  photometric  scale 
shall  be  noted.  This  observation  is  to  be  made  four  times  in  all,  and 
the  mean  of  the  results  taken.  The  time  that  the  meter  hand  takes 
to  make  exactly  two  revolutions  shall  then  be  observed  by  the  aid  of 
a  stop-clock  or  stop-watch.  The  mean  of  the  four  readings  of  the 
photometric  scale  shall  be  multiplied  by  the  number  of  seconds  in  the 
time  recorded  and  by  the  aerorthometer  reading  and  divided  by  120. 
The  quotient  is  the  illuminating  power. 

If  the  gas  is  so  rich  that  it  cannot  be  made  to  burn  at  the  prescribed 
rate  without  tailing  above  the  chimney  or  smoking,  or  if  the  burner 
cannot  be  pushed  far  enough  away  to  produce  equality  of  illumination 
on  the  photoped,  the  rate  must  be  reduced  until  the  flame  burns 
properly  within  the  chimney,  or  a  balance  is  produced  when  the 
burner  is  at  the  far  end  of  the  slide.  In  all  other  respects  the  testing 
and  calculation  shall  be  made  as  described. 

If,  in  very  exceptional  circumstances,  the  aerorthometer  scale  or 
the  table  does  not  include  the  conditions  that  are  met  with,  the  Gas 
Examiner  shall  in  calculating  the  illuminating  power  use  the  formula 
printed  below  the  table. 

Each  testing  place  must  be  provided  with  a  standard  clock  that 
will  go  for  a  week  without  re- winding. 

The  Gas  Examiner  shall,  at  least  once  a  week,  compare  the  stop- 
clock  in  the  testing  place  with  the-standard  clock  or  with  his  watch. 

The  Gas  Examiner  shall  enter  in  his  oook  the  particulars  of  every 
testing  of  illuminating  power  made  by  him  at  the  testing  places, 
during  or  immediately  after  such  testing  ;  and  in  the  case  of  any  test- 
ing which  he  rejects  he  shall  also  state  the  cause  of  rejection.  No 
testing  is  to  be  rejected  on  the  ground  that  the  result  seems  improbable. 

II. — TESTINGS  WITH  THE  STANDARD  FLAT  FLAME  BURNER. 

The  testings  for  illuminating  power  made  with  the  flat  flame  burner 
shall  be  made  at  such  times  as  the  Controlling  Authority  shall 
direct.  The  burner  shall  be  Bray's  "No.  7  Economiser"  fitted  over 
a  Bray's  "No.  4  Emulator."  The  testings  made  with  it  shall  be 
conducted  in  the  same  way  as  those  with  the  Argand.  A  new  burner 
shall  be  used  every  week. 

If  the  gas  is  so  poor  that  the  burner  cannot  be  brought  near  enough 
to  produce  equality  of  illumination  on  the  photoped,  the  rate  of  con- 
sumption must  be  increased,  until  a  balance  is  produced  when  the 
burner  is  at  the  near  end  of  the  slide.  In  all  other  respects  the 
testing  shall  be  carried  out  as  described. 

As  to  the  Times  and  Mode  of  Testing  for  Sulphuretted  Hydrogen, 

The  apparatus  to  be  used  in  testing  gas  for  the  presence  of 
sulphuretted  hydrogen  is  figured  in  Appendix  H.  The  gas  as  it 
leaves  the  service  pipe  shall  be  passed  through  the  glass  vessel  in 
which  are  suspended  slips  of  bibulous  paper  which  have  been  recently 
moistened  by  dipping  them  in  a  solution  consisting  of  100  grains  of 
crystallised  acetate  of  lead  dissolved  in  100  cubic  centimetres  of 
water. 


ILLUMINATING    POWER    AND    PURITY    OF    GAS.  415 

One  testing  shall  be  made  daily. 

In  making  the  testing,  gas  shall  be  turned  on  to  the  apparatus,  and 
lit  at  the  burner  as  soon  as  the  air  has  been  swept  out.  When  the 
gas  has  burnt  for  three  minutes  it  is  to  be  turned  off,  and  one  of  the 
slips  of  paper  is  to  be  compared  with  another  similar  slip  which  has 
not  been  exposed  to  the  gas.  The  gas  is  to  be  taken  as  showing  the 
presence  of  sulphuretted  hydrogen  if  the  slip  of  paper  which  has  been 
exposed  to  it  is  unmistakably  the  darker  of  the  two. 

In  this  event  two  of  the  test-slips  which  have  been  exposed  to  the 
gas  shall  be  placed  in  a  stoppered  bottle  and  kept  in  the  dark  at  the 
testing  place  ;  one  of  the  remaining  slips  shall  be  forwarded  with  each 
daily  report,  and  the  comparison  slip  shall  be  retained  by  the  Gas 
Examiner  for  the  use  of  the  Chief  Gas  Examiner. 

The  Gas  Examiner  in  making  his  return  shall  write  either 
"  present "  or  "  absent  "  as  the  case  may  be. 

As  to  the  Mode  of  Testing  for  Sulphur  Compounds  other  than 
Sulphuretted  Hydrogen, 

This  testing  shall  be  made  on  such  days  as  the  Controlling 
Authority  shall  direct.  A  description  of  the  apparatus  to  be 
employed  is  given  in  Appendix  K.  It  is  to  be  set  up  in  a  room 
or  clc  set  where  no  other  gas  is  burning.  The  gas  shall  pass  through  a 
meter  by  reference  to  which  the  rate  of  flow  can  be  adjusted,  and 
which  is  provided  with  a  self-acting  movement  for  shutting  oft  the 
gas  when  ten  cubic  feet  have  passed. 

Pieces  of  sesqui-carbonate  of  ammonia,  from  the  surface  of  which 
any  efflorescence  has  been  removed,  are  to  be  placed  round  the  stem 
of  the  burner.  The  index  of  the  meter  is  to  be  then  turned  forward 
to  the  point  at  which  the  catch  falls  and  will  again  support  the 
lever-tap  in  the  horizontal  position.  The  lever  is  made  to  rest 
against  the  catch  so  as  to  turn  on  the  gas.  The  index  is  turned  back 
to  a  little  short  of  zero,  and  the  burner  lighted.  When  the  index  is 
«lose  to  zero  the  trumpet-tube  is  placed  in  position  on  the  stand  and 
its  narrow  end  connected  with  the  tubulure  of  the  condenser.  At 
the  same  time  the  long  chimney -tube  is  attached  to  the  top  of  the 
condenser. 

As  soon  as  the  testing  has  been  started,  a  first  reading  of  the 
aerorthometer  is  to  be  made  and  recorded,  and  a  second  reading  as 
near  as  may  be  to  the  time  at  which  the  gas  is  shut  off.  The  rate  of 
burning,  which  with  practice  can  be  judged  very  nearly  by  the 
height  of  the  flame,  is  to  be  adjusted,  by  timing  the  index  of  the 
meter,  to  about  half  a  cubic  foot  of  gas  per  hour. 

After  each  testing  the  flask  or  beaker,  which  has  received  the 
liquid  products  of  the  combustion  of  the  ten  cubic  feet  of  gas,  is  to  be 
emptied  into  a  measuring  cylinder  and  then  replaced  to  receive  the 
washings  of  the  condenser.  Next  the  trumpet-tube  is  to  be  removed 
and  well  washed  out  into  the  measuring  cylinder.  The  condenser  is 
then  to  be  flushed  twice  or  thrice  by  pouring  quickly  into  the  mouth 
of  it  40  or  50  cubic  centimeters  of  distilled  water.  These  washings 
are  brought  into  the  measuring  cylinder,  whose  contents  are  to  be 
well  mixed  and  divided  into  two  equal  parts. 


416  GAS  ENGINEER'S  POCKET-BOOK. 

One-half  of  the  liquid  so  obtained  is  to  be  set  aside,  in  case  it 
should  be  desirable  to  repeat  the  determination  of  the  amount  of 
sulphur  which  the  liquid  contains. 

The  other  half  of  the  liquid  is  brought  into  a  flask,  or  beaker 
covered  with  a  large  watch-glass,  treated  with  hydrochloric  acid 
sufficient  in  quantity  to  leave  an  excess  of  acid  in  the  solution,  and 
then  raised  to  the  boiling  point.  An  excess  of  a  solution  of  barium 
chloride  is  Inow  to  be  added,  and  the  boiling  continued  for  five 
minutes.  The  vessel  and  its  contents  are  to  be  allowed  to  stand  till 
the  bari-im  sulphate  has  settled  at  the  bottom  of  the  vessel,  after 
which  the  clear  liquid  is  to  be  as  far  as  possible  poured  off  through  a 
paper  filter.  The  remaining  liquid  and  barium  sulphate  are  then  to 
be  brought  on  to  the  filter,  and  the  latter  is  to  be  well  washed  with 
hot  distilled  water.  (In  order  to  ascertain  whether  every  trace  of 
barium  chloride  and  ammonium  chloride  has  been  removed,  a 
small  quantity  of  the  washings  from  the  filter  should  be  placed  in  a 
test-tube,  and  a  drop  of  a  solution  of  silver  nitrate  added ;  should 
the  liquid,  instead  of  remaining  perfectly  clear,  become  cloudy,  the 
washing  must  be  continued  until  on  repeating  the  test  ixo  cloudiness 
is  produced.)  Dry  the  filter  with  its  contents,  and  transfer  it  into  a 
weighed  platinum  crucible.  Heat  the  crucible  over  a  lamp,  in- 
creasing the  temperature  gradually,  from  the  point  at  which  the 
paper  begins  to  char,  up  to  bright  redness.*  When  no  black  particles 
remain,  allow  the  crucible  to  cool  :  place  it  when  nearly  cold  in  a 
desiccator  over  strong  sulphuric  acid,  and  again  weigh  it.  The 
difference  between  the  first  and  second  weighings  of  the  crucible 
will  give  the  number  of  grains  of  barium  sulphate.  Multiply  this 
number  by  11  and  divide  by  4  ;  the  result  is  the  number  of  grains  of 
sulphur  in  100  cubic  feet  of  the  gas. 

This  number  is  to  be  corrected  for  the  variations  of  temperature 
and  atmospheric  pressure  in  the  manner  indicated  under  the  head 
of  Illuminating  Power,  with  this  difference,  that  the  mean  of  the 
first  and  second  aerorthometer  readings  shall  be  taken  as  the 
reading. 

The  correction  by  means  of  the  aerorthometer  reading  may  be 
made  imost  simply  and  with  sufficient  accuracy  in  the  following 
manner : — 

When  the  aerorthometer  reading  is  between 

•955- '965,  -965--9T5,  -975-'985,  '9S5--995, 
diminish    the  number 
of  grains  of  sulphur  by         4,  3,  2,  1  per  cent. 

When  the  aerorthometer  reading  is  between  '995-1 '005,  no  correc- 
tion need  be  made. 

When  the  aerorthometer  reading  is  between 

r005-r016,  1-015-1-025,  1-025-1-035, 
increase  the  number  of 
grains  of  sulphur  by ...  1,  2.  3  per  cent. 

*  An  equally  good  and  more  expeditious  method  is  to  drop  the 
filter  with  its  contents,  drained  but  not  dried,  into  the  red-hot  crucible. 


ILLUMINATING   POWER   AND    PURITY    OF    GAS.  417 

Example : — 

Grains  of  barium  sulphate  from  5  cubic 

feet  of  gas 

Multiply  by  11  and  divide  by  4      .      . 

4)114-4 

Grains  of  sulphur  in  100  cubic  feet  of 

gas  (uiicorrected)        .        .        .      28'60 
Add  28-6  X  ^j  =      .         .        .     .         '57 

Grains  of  sulphur  in  100  cubic  feet  of  Kesult : 

gas  (corrected)   ....     29'17      29'2  grains. 

The  aerorthometer  reading  is  the  reciprocal  of  the  tabular 
number.  The  Gas  Examiner  shall,  not  less  often  than  once  a  month, 
compare  the  aerorthometer  reading  with  the  reciprocal  of  the  tabular 
number  deduced  from  observations  of  the  barometer  and  thermometer, 
and  if  there  is  a  difference  of  more  than  one-half  per  cent,  the 
aerorthometer  is  to  be  readjusted. 

As  to  the  Mode  of  Testing  the  Calorific  Power  of  the  Gas. 

This  testing  shall  be  made  on  such  days,  as  the  controlling  authority 
shall  direct. 

The  calorimeter  to  be  used  in  testing  the  calorific  power  of  the 
gas  shall  be  one  which  has  been  examined  and  certified  by  the  Gas 
Eeferees.  A  description  of  the  calorimeter  is  given  in  Appendix  L. 

In  order  to  test  the  gas  for  calorific  power,  the  gas  shall  first  pass 
through  a  meter  and  a  balance  governor  of  the  same  construction  as 
those  on  the  photometer  table.  It  shall  then  be  led  to  the  gas  inlet 
in  the  base  of  the  calorimeter.  The  gas  shall  be  turned  on  and 
lighted,  and  the  tap  of  the  calorimeter  shall  be  so  adjusted  as  to 
allow  the  meter  hand  to  make  one  turn  in  from  60  to  75  seconds. 
The  water  shall  be  turned  on  so  that  when  the  regular  flow  through 
the  calorimeter  has  been  established  a  little  may  pass  the  overflow  of 
the  funnel  and  trickle  over  into  the  sink.  Water  must  be  poured  in 
through  one  of  the  holes  in  the  lid  until  it  begins  to  run  out  at  the 
condensation  outlet.  The  calorimeter  may  then  be  placed  upon  its 
base.  The  measuring  vessel  carrying  the  change-over  funnel  shown 
in  Fig.  16,  p.  432,  should  then  be  placed  in  position  in  the  sink 
so  that  the  outlet  water  is  led  into  the  sink.  The  hot  water  outlet 
tube  of  the  calorimeter  should  be  above  but  should  not  touch 
the  change-over  funnel.  After  an  interval  of  not  less  than  20 
minutes  the  Gas  Examiner,  after  bringing  the  reading  glasses  into 
position  on  the  thermometers  used  for  measuring  the  temperature  of 
the  inlet  and  outlet  water,  shall  then  make  the  following  observa- 
tions. When  the  meter  hand  is  at  75  he  shall  read  the  inlet  tempera- 
ture ;  when  it  reaches  100  he  shall  move  the  funnel  so  as  to  direct 
the  outflow  into  the  measuring  vessel  and  at  the  same  time  he  shall 
start  the  stop-clock  or  a  stop-watch.  When  the  meter  hand  reaches 
25  he  shall  make  the  first  reading  of  the  outlet  temperature.  He 

a.E.  E  E 


418  GAS  ENGINEER'S  POCKET-EOOK. 

shall  continue  to  read  the  outlet  temperature  at  every  quarter  turn 
until  fifteen  readings  have  been  taken.  The  meter  hand  will  then  be 
at  75.  He  shall  also  at  every  turn  of  the  meter  except  the  last  make 
a  reading  of  the  inlet  temperature  when  the  meter  hand  is  between 
75  and  1UO.  When  the  meter  hand  reaches  100  after  the  last  outlet  tem- 
perature has  been  read,  the  Gas  Examiner  shall  shift  the  funnel  so  as  to 
direct  the  outlet  water  into  the  sink  again  and  at  the  same  time  stop 
the  clock  or  watch.  The  barometer  and  the  thermometers  showing 
the  temperatures  of  the  effluent  gas,  of  the  air  near  the  calorimeter 
and  of  the  gas  in  the  meter,  shall  then  be  read.  The  time  shown  by 
the  stop-clock  shall  be  recorded.  The  mean  of  the  four  readings  of 
the  inlet  te.nperature  is  to  be  subtracted  from  the  mean  of  the  fifteen 
readings  of  the  outlet  temperature  and  the  difference  is  to  be  multi- 
plied by  3  and  by  the  number  of  litres  of  water  collected  and  the  pro- 
duct is  to  be  divided  by  the  tabular  number.  The  difference  in  degrees 
centigrade  of  the  temperature  of  the  effluent  gas  and  of  the  surrounding 
air  shall  be  taken,  and  one-sixth  of  this  difference  shall  be  added  to  the 
result  previously  found  if  the  effluent  gas  is  the  warmer  of  the  two,  or 
subtracted  if  the  effluent  gas  is  the  cooler  of  the  two.*  The  result 
is  the  gross  calorific  power  of  the  gas  in  calories  per  cubic  foot. 

la  addition  to  the  observations  described,  the  amount  of  condensed 
water  resulting  frjm  the  combus  tion  of  the  gas  shall  be  measured. 
For  this  purpose  the  condensati3n  water  shall  be  led  into  a  flask 
not  less  than  20  minutes  after  the  calorimeter  has  been  placed  in 
^osition.  The  amount  collected  in  not  less  than  30  minutes  shall 
J&  measured,  the  time  of  collection  having  been  accurately  noted. 

The  number  of  cubic  centimetres  collected  shall  be  multiplied  by 
the  number  of  seconds  in  the  time  indicated  by  the  stop-clock  and 
by  the  number  1-86.  The  number  of  seconds  in  the  time  during  which 
the  condensed  water  was  being  collected  shall  be  multiplied  by  the 
tabular  number.  The  first  product  shall  be  divided  by  the  second. 
The  quotient  is  to  bs  subtracted  from  the  gross  calorific  power.  The 
difference  is  the  net  calorific  power  in  calories  per  cubic  foot.  The 
corresponding  values  of  the  gross  and  net  calorific  power  in  British 
Thermal  Units  can  be  obtained  by  multiplying  the  number  of 
calories  by  3-908. 

A  form  on  which  the  Gas  Examiner  may  conveniently  set  down  his 
observations  and  the  whole  of  the  figures  needed  for  the  calculation 
is  given  at  the  end  of  Appendix  L.  The  figures  in  italic  type  are 
specimen  figures,  and  represent  such  as  might  be  written  by  the  Gas 
Examiner. 

As  to  the  Mode  of  Testing  the  Pressure  at  which  Gas  is  Supplied. 

Testings  of  pressure  shall  be  made  at  such  times  and  in  such  places 
as  the  Controlling  Authority  may  from  time  to  time  appoint  (Gas- 
light and  Coke  and  other  Gas  Companies  Acts  Amendment  Act, 
1880,  Section  6).  In  order  to  make  this  testing  the  Gas  Examiner 
shall  unscrew  the  governor  and  burner  of  one  of  the  ordinary  public 
lamps,  and  shall  attach  in  their  stead  a  portable  pressure-gauge.  In 

*  This  correction  has  been  found  by  experiment. 


ILLUMINATING    POWER   AND   PURITY   OF    GAS.  41  i> 

places  where  incandescent  burners  are  used  for  street-lighting,  one 
street  lamp  in  each  street  or  group  of  streets  may  be  provided  under 
the  lantern  with  a  branch  closed  by  a  screw  stopper.  The  Gas 
Examiner  shall  in  such  cases  connect  the  pressure-gauge  by  screwing 
to  it  an  |_-shaped  pipe  fitted  with  a  union,  by  means  of  which  it  may 
be  connected  to  the  service  pipe  in  the  place  of  the  screw  stopper. 
The  |_-shaped  pipe  is  to  be  of  such  dimensions  as  to  enable  the 
pressure-gauge  to  be  fixed  outside  the  lantern  but  at  about  the  game 
level  as  the  incandescent  burner.  It  should  be  provided  with  a  tap. 

The  gauge  to  be  used  for  this  purpose  consists  of  an  ordinary 
pressure-gauge  enclosed  in  a  lantern,  which  also  holds  a  candle  for 
throwing  light  upon  the  tubes  and  scale.  The  difference  of  level  of 
the  water  in  the  two  limbs  of  the  gauge  is  read  by  means  of  a  sliding 
scale,  the  zero  of  which  is  made  to  coincide  with  the  top  of  the  lower 
column  of  liquid. 

The  Gas  Examiner  having  fixed  the  gauge  gas-tight,  and  as  nearly 
as  possible  vertical  on  the  pipe  of  the  lamp,  and  having  opened  the 
cocks  of  the  lamp  and  gauge,  shall  read  and  at  once  record  the 
pressure  shown.  From  the  observed  pressure  one-tenth  of  an  inch  is 
to  be  deducted  to  correct  for  the  difference  between  the  pressure  of 
gas  at  the  top  of  the  lamp  column  and  that  at  which  it  is  supplied  to 
the  basement  of  neighbouring  houses. 

The  pressure  prescribed  in  the  Acts  of  the  three  Metropolitan  Gas 
Companies  is  to  be  such  as  to  balance  from  midnight  to  sunset  a 
column  of  water  not  less  than  one  inch  in  height. 

Meters. 

Each  of  the  meters  used  for  measuring  the  gas  consumed  in  making 
the  various  testings  is  constructed  with  a  measuring  drum  which 
allows  one-twelfth  of  a  cubic  foot  of  gas  to  pass  for  every  revolution. 
A  hand  is  fastened  directly  to  the  axle  of  this  drum  and  passes  over 
a  dial  divided  into  one  hundred  equal  divisions.  The  dial  and  hand 
are  protected  by  a  glass.  In  the  meter  employed  in  testing  the  purity 
of  gas  the  pattern  of  dial  for  showing  the  number  of  revolutions  and 
the  automatic  cut-off  hitherto  in  use  shall  be  retaineo  but  in  the 
meter  employed  for  testing  illuminating  power,  only  the  dial  above 
described  is  needed.  The  meters  should  be  provided  with  Fahrenheit 
thermometers.  The  stop-clock  may  be  either  attached  to  the  meter 
or  separate. 

The  meters  used  for  measuring  the  gas  consumed  in  making  the 
various  testings  having  been  certified  by  the  Referees,  shall,  at  least 
once  in  seven  days,  be  proved  by  the  Gas  Examiners  by  means  of  the 
Referees'  one-twelfth  of  a  cubic  foot  measure. 

No  meter  other  than  a  wet  meter  shall  be  used  in  testing  the  gas 
under  these  instructions. 


EE2 


420 


GAS  ENGINEER'S  POCKET-BOOK. 


APPENDIX  A. 
TJie  Ten- Candle  Pentane  Lamp. 

Mr.  Harcourt's  Ten-Candle  Pentane  Lamp  is  one  in  which  air  is 
saturated  with  peutane  vapour,  the  air-gas  so  formed  descending  by 
its  gravity  to  a  steatite  ring  burner.  The  flame  is  drawn  into  a 

definite  form,  and 
the  top  of  it  is 
hidden  from  view 
by  a  long  brass 
chimney  above  the 
steatite  burner.  The 
chimney  is  sur- 
rounded by  a  larger 
brass  tube,  in  which 
the  air  is  warmed  by 
the  chimney,  and  so 
tends  to  rise.  This 
makes  a  current 
which,  descending 
through  another 
tube,  supplies  air  to 
the  centre  of  the 
steatite  ring.  No 
glass  chimney  is 
required,  and  no 
exterior  means  have 
to  be  employed  to 
drive  the  pentane 
vapour  through  the 
burner. 

Figure  1  shows 
the  general  appear- 
ance of  the  lamp. 
The  saturator  A  is  at 
starting  about  two- 
thirds  filled  with 
pentane.*  It  should 

*  CAUTION. — Pen- 
tane is  extremely  in- 
flammable ;  it  gives 
off  at  ordinary  tem- 
peratures a  heavy 
vapour  which  is 
liable  to  ignite  at  a 
flame  at  a  lower 
level  than  the  liquid. 
TJie  saturator  must 
never  have  pentane 
poured  into  it  when 
in  position,  if  the  lamp  or  tJie  gas  of  the  pnoiometer  is  alight. 


ILLUMINATING  POWER  AND   PURITY  OF  GAS.  421 

be  replenished  from  time  to  time  so  that  the  height  of  liquid  as  seen 
against  the  windows  may  not  be  less  than  one-eighth  of  an  inch.  The 
saturator  A  is  connected  with  the  burner  B  by  means  of  a  piece  of 
wide  india-rubber  tube.  The  rate  of  flow  of  the  gas  can  be  regulated 
by  the  stop-cock  S2,  or  by  checking  the  ingress  of  air  at  S^  For  this 
latter  purpose  a  metal  cone,  acting  as  a  damper,  is  suspended  by  its 
apex  from  one  end  of  a  lever,  to  the  other  end  of  which  is  attached  a 
thread  for  moving  the  cone  up  or  down.  The  lever  is  supported  by 
an  upright  arm  clamped  to  the  upper  end  of  the  stop-cock  immediately 
beneath  the  cone.  From  the  top  of  the  lamp  the  thread  descends  to 
a  small  pulley  on  the  table,  and  thence  passes  horizontally  to  the  end 
of  a  screw  moving  in  a  small  block,  by  turning  which  the  Gas 
Examiner  can  regulate  the  lamp  without  leaving  his  seat.  It  is  best 
so  to  turn  the  stop-cock  82  as  to  allow  the  flame  to  be  definitely  too 
high,  but  not  to  turn  it  full  on,  before  letting  down  the  regulating 
cone  to  its  working  position.  Both  stop-cocks  should  be  turned  off 
when  the  lamp  is  not  alight. 

The  chimney  tube  C  C  should  be  turned  so  that  no  light  passing 
through  the  mica  window  near  its  base  can  fall  upon  the  photoped. 
The  lower  end  of  this  tube  should,  when  the  lamp  is  cold,  be  set  47 
millimeters  above  the  steatite  ring  burner.  A  cylindrical  boxwood 
gauge,  47  millimeters  in  length  and  32  in  diameter,  is  provided  with 
the  lamp  to  facilitate  this  adjustment.  The  exterior  tube  D  com- 
municates with  the  interior  of  the  ring-burner  by  means  of  the 
connecting  box  above  the  tube  $  and  the  bracket  F  on  which  the 
burner  B  is  supported.  A  conical  shade  G  is  provided.  This  should 
be  placed  BO  that  the  whole  surface  of  the  flame  beneath  the  tube  C 
may  be  seen  at  the  photoped  through  the  opening. 

The  lamp  should  be  adjusted '  by  its  levelling  screws  so  that  the 
tube  E,  as  tested  with  a  plumb-line,  is  vertical,  and  so  that  the  upper 
Burface  of  the  steatite  burner  is  353  millimeters  from  the  table.  A 
gauge  is  provided  to  facilitate  this  latter  measurement.  The  tube  C 
is  brought  centrally  over  the  burner  by  means  of  the  three  adjusting 
screws  at  the  base  of  the  tube  D.  These  three  screws  should  not  be 
quite  screwed  up,  but  only  sufficiently  so  to  keep  the  chimney  tube 
central.  The  adjustment  is  facilitated  by  nvaans  of  the  boxwood 
gauge. 

When  the  lamp  is  in  use  the  stop-cocks  are  to  be  regulated  so  that 
the  tip  of  the  flame  is  about  half-way  between  the  bottom  of  the 
mica  window  and  the  cross-bar.  A  variation  of  a  quarter  of  an  inch 
either  way  has  no  material  influence  upon  the  light  of  the  flame. 
The  saturator  A  should  be  placed  upon  the  bracket  as  far  from  the 
central  column  as  the  stop  at  the  end  will  allow.  If  it  is  found  that, 
after  the  lamp  has  been  lighted  for  a  quarter  of  an  hour,  the  tendency 
of  the  flame  is  to  become  lower,  the  saturator  may  be  placed  a  little 
nearer  the  central  column. 

To  prevent  a  gradual  accumulation  of  dust  in  either  the  burner  or 
the  air-passage,  a  small  cover  of  the  size  of  the  top  of  B  and  shaped 
like  the  lid  of  a  pill-box  should  be  kept  upon  the  lamp  when  not  in 
use. 


422  GAS  ENGINEER'S  POCKET-BOOK. 

APPENDIX  B. 

The  pentane  to  be  used  in  the  10-candle  lamp  should  be  prepared 
and  tested  in  the  following  manner  : — 

PREPARATION. — Light  American  petroleum,  such  as  is  known  as 
gasoline  and  used  for  making  air-gas,  is  to  be  further  rectified  by 
three  distillations,  at  55°  C.,  50°,  and  45°  in  succession.  The  dis- 
tillate at  45°  is  to  be  shaken  up  from  time  to  time  during  two  periods 
of  not  less  than  three  hours  each  with  one-tenth  its  bulk  of  (1)  strong 
sulphuric  acid,  (2)  solution  of  caustic  soda.  After  these  treatments 
it  is  to  be  again  distilled,  and  that  portion  is  to  be  collected  for  use 
which  comes  over  between  the  temperatures  of  25°  and  40°.  It  will 
consist  chiefly  of  pentane,  together  with  small  quantities  of  lower 
and  higher  homologues  whose  presence  does  not  affect  the  light  of  the 
lamp. 

TESTING.— The  density  of  the  liquid  pentane  at  15°  C.  should  not 
be  less  than  0*6235  nor  more  than  0*626  as  compared  with  that  of 
water  of  maximum  density.  The  density  of  the  pentane  when 
gaseous,  as  compared  with  that  of  hydrogen  at  the  same  tempera- 
ture and  under  the  same  pressure,  may  be  taken.  This  is  done  most 
readily  and  exactly  by  Gay  Lussac's  method,  under  a  pressure  of 
about  half  an  atmosphere  and  at  temperatures  between  25°  and  35°. 
The  density  of  gaseous  pentane  should  lie  between  36  and  38. 

Any  admixture  with  pentane  of  hydrocarbons  belonging  to  other 
groups  and  having  a  higher  photogenic  value,  such  as  benzene  or 
amylene,  must  be  avoided.  Their  presence  may  be  detected  by  the 
following  test.  Bring  into  a  stoppered  4-oz.  bottle  of  white  glass 
10  cc.  of  nitric  acid,  specific  gravity  T32  (made  by  diluting  pure 
nitric  acid  with  half  its  bulk  of  water) ;  add  1  cc.  of  a  dilute  solu- 
tion of  potassium  permanganate,  containing  O'l  gram  of  perman- 
ganate in  200  cc.  Pour  into  the  bottle  50  cc.  of  the  sample  of 
pentane,  and  shake  strongly  during  five  successive  periods  of  20 
seconds.  Tf  no  hydrocarbons  other  than  paraffins  are  present,  the 
pink  colour  though  somewhat  paler,  will  still  be  distinct ;  if  there  is 
an  admixture  of  as  much  as  £  per  cent,  of  amylene  or  benzene,  the 
colour  will  have  disappeared. 

APPENDIX  D. 
The  Table  Photometer. 

The  several  parts  of  the  apparatus  stand  upon  a  well-made  au<l 
firm  table,  5  feet  6  inches  by  3  feet  6  inches,  and  2  feet  5  inches  high. 
The  upper  surface  of  this  table  is  smooth,  level,  and  dead  black. 
Upon  this  are  placed  or  clamped  in  the  positions  shown  in  Fig.  3 : — 

(1.)— The  Gas  Meter. 

(2.)— The  Gas  Governor. 

(3.)— The  Regulating  Tap. 
•  (4.) — The  "  Metropolitan  Argand  Burner,  No.  2,"  and  Sliding  Base. 

(5.)— The  Flat  Flame  Burner  and  Sliding  Base. 

(6.)— The  Slide,  Connecting  Bod  and  Photometric   Scale,  and 
Index. 


ILLUMINATING   POWER  AND  PURITY   OP   GAS. 

(7.)— The  Connecting  Pipes. 

(8.) — The  Pentane  Ten-Candle  Lamp. 

(9.)— The  Photoped. 


423 


FIG.  3. 


424\       GAS  ENGINEER'S  POCKET-BOOK. 

CIO.)— The  Aerorthometer. 
(11.)— The  Stop  Clock. 

(12.) — Dark  Screens ;  Mirrors  ;  Measuring  Bod  ;  Small  Block,  and 
Pulley. 

APPENDIX  B. 

The  burner  which  has  been  adopted  as  the  standard  burner  for 
testing  gas  was  devised  by  Mr.  Charles  Carpenter,  and  has  been 
called  by  kirn  "  The  Metropolitan  Argand  Burner,  No.  2." 

A  full-sized  drawing  showing  details  is  given  in  Fig.  10,  on  which 
also  are  marked  the  important  dimensions.  While  these  are  given 
in  every  case  to  the  nearest  thousandth  of  an  inch,  this  degree  of 
accuracy  is  not  essential.  The  important  dimensions  are  those 
governing  the  gas  and  air  passages,  but  all  should  be  adhered  to  as 
nearly  as  workshop  practice  allows. 

The  annular  chamber  from  which  the  gas  issues  is  made  of  steatite. 

The  chimney  to  be  used  with  this  burner  is  6  inches  long  and 
If  inch  in  internal  diameter. 

Each  testing  place  is  provided  with  a  box  containing  two  wire 
gauges,  one  0-058  inch,  and  the  other  0*062  inch  in  diameter.  The 
Gas  Examiner  must  once  in  every  month  pass  the  smaller  gauge 
through  every  hole  in  the  burner,  so  as  to  clear  out  any  loose 
obstruction  or  detect  any  hard  concretion  that  might  interfere  with 
the  proper  discharge  of  the  gas.  He  should  at  the  same  time  satisfy 
himself  that  the  larger  gauge  will  not  pass  through  the  holes. 


ILLUMINATING   POWER  AND   PURITY    OF   GAS. 


425 


f-940 
Y -ffg- H 

L '-IT5 «\ 


THE  METROPOLITAN  ARGAND  BURNER,  No.  2 
Fig.  10. 


426 


GAS  ENGINEER'S  POCKET-BOOK. 


APPENDIX  G. 

TABULAR  NUMBERS,   BEING  A  TABLE  TO  FACILITATE  THE  CORRECTION    Ql 

TURES  AND  UNDER  DIFFERENT 


Bar. 

Thermometer  —  Fahrenheit. 

40° 

42° 

44° 

46° 

48° 

50° 

52° 

54° 

56° 

58° 

60° 

280 

•979 

•974 

•970 

•965 

•960 

•956 

•951 

•946 

•942 

•937 

•932 

28-1 

•983 

•978 

•973 

•969 

•964 

•959 

•955 

•951 

•945 

•941 

•936 

282 

•986 

•981 

•977 

•972 

•1>67 

•963 

•958 

•953 

•949 

•944 

•939 

283 

•990 

•985 

•980 

•976 

•971 

•966 

•961 

•957 

•952 

•947 

•942 

28-4 

•993 

•988 

•984 

•979 

•974 

•970 

•965 

•960 

•955 

•951 

•946 

285 

•997 

•992 

•987 

•983 

•978 

•973 

•968 

•964 

•959 

•954 

•949 

286 

1-001 

•995 

•991 

•986 

•981 

•977 

•972 

•967 

•962 

•958 

•953 

287 

1-001 

•999 

•994 

•990 

•985 

•980 

•975 

•970 

•966 

•961 

•956 

288 

1-007 

1-003 

•998 

•993 

•988 

•984 

•979 

•974 

•969 

•964 

•959 

28-9 

1-011 

1-006 

1-001 

•997 

•992 

•987 

•982 

•977 

•973 

•968 

•963 

290 

1-014 

1-010 

1-005 

1-000 

•995 

•990 

•986 

•981 

•976 

•971 

•966 

291 

1-018 

1-013 

1-008 

1-004 

•999 

•994 

•989 

•984 

•979 

•975 

•969 

292 

1-021 

1-017 

1-012 

1-007 

1-002 

•997 

•992 

•988 

•982 

•978 

'  -973 

293 

1-025 

1-020 

1-015 

rou 

1-006 

1-001 

•996 

•991 

•986 

•981 

•976 

294 

1-028 

1-024 

1-019 

1-014 

1-009 

1-004 

•999 

•995 

•990 

•985 

•980 

295 

1-032 

1-027 

1-022 

1-018 

1-013 

1-008 

1-003 

•998 

•993 

•988 

•983 

296 

1-036 

1-031 

1-026 

1-021 

1-016 

1-011 

1-006 

1-001 

•996 

•992 

•986 

29-7 

1-039 

1-034 

1-029 

•025 

1-019 

1-015 

1-010 

L-005 

1-000 

•995 

•990 

298 

1-043 

1-038 

1-033 

•028 

1-023 

1-018 

1-013 

1-008 

1-003 

•998 

•993 

299 

1-046 

1-041 

1-036 

•031 

1-026 

1-022 

1-017 

1-012 

1-007 

1-002 

•997 

300 

1-050 

1-045 

1-040 

•035 

1-030 

1-025 

1-020 

1-015 

1-010 

1-005 

i-ooc 

301 

1-053 

1-048 

1-043 

•038 

1-033 

1-029 

1-024 

1-019 

1-014 

1-009 

1-002 

302 

1-057 

1-052 

1-047 

•042 

1-037 

1-032 

•027 

1-022 

1-017 

1-012 

1-007 

303 

1-060 

1-055 

1-050 

1-045 

1-040 

1-036 

•030 

1-025 

1-020 

1-015 

1-01C 

304 

1-064 

1-059 

1-054 

1-049 

1-044 

1-039 

•034 

1-029 

1-024 

1-019 

1-01-1 

305 

1-067 

1-062 

1-057 

1-052 

1-047 

1-042 

1-037 

1-032 

1-027 

1-022 

1-01? 

306 

1-071 

1-066 

1-061 

1-056 

1-051 

1046 

•041 

1-036 

1-031 

1-026 

1-02C 

307 

1-074 

1-069 

1-064 

1-059 

1-054 

1-049 

•044 

1-039 

1-034 

1-029 

1-024 

308 

1-078 

1-073 

1-068 

1-063 

1-058 

1-053 

•048 

1-043 

1-037 

1-032 

1-027 

309 

1-081 

1-076 

1-071 

1-066 

1-061 

1-056 

•051 

1-046 

1-041 

1-036 

1-031 

310 

1-085 

1-080 

1-075 

1-070 

1-065 

1-060 

•055 

1-049 

1-044 

1-039 

1-034 

%*  The  numbers  in  the  above  table  have  been  calculated  from  the  formi 

•  temperature  on  the  Fahrenheit  scale,  and  a  the  tension  of  aqueous  vapc 

volume  at  60°  and  30  incl 


ILLUMINATING   POWER   AND   PURITY   OF    GAS. 


APPENDIX  G. 

THE  VOLUME  OF  GAS  MEASURED    OVER    WATER    AT    DIFFERENT    TEMPERA- 
ATMOSPHERIC  PRESSURES. 


Bar. 

Thermometer  —  Fahrenheit. 

62° 

64° 

66° 

68° 

70° 

72.° 

74° 

76° 

78° 

8(X° 

82° 

84° 

280, 

•927 

•922 

•917 

•912 

•907 

•902 

•897 

•892 

887 

•881 

•875 

•870 

281 

•930 

•926 

•921 

•916 

•911 

•905 

•900 

•895 

•890 

•884 

•879 

•873 

282 

•934 

•929 

•924 

•919 

•914 

•909 

•904 

•898 

•893 

•887 

•882 

•876 

283 

•937 

•932 

•928 

•922 

•917 

•912 

•907 

•902 

•896 

•891 

•885 

•880 

284 

•941 

•936 

•931 

•926 

•921 

•915 

•910 

•905 

•900 

•894 

•888 

•883 

285 

•944 

•939 

•934 

•929 

•924 

•919 

•914 

•908 

•903 

•897 

•892 

•886 

286 

•947 

•943 

•938 

•932 

•927  1    -922 

•917 

•912 

•906 

•901 

•895 

•889 

28-7 

•951 

•946 

•941 

•936 

•931 

•925 

•920 

•915 

•909 

•904 

•898 

•*93 

288 

•954 

•949 

•944 

•939 

•934 

•929 

•924 

•918 

•913 

•907 

•901 

•896 

289 

•958 

•953 

•948 

•942 

•937 

•932 

•927 

•921 

•916 

•910 

•905 

•899 

290 

•961 

•956 

•951 

•946 

•941 

•935 

•930 

•925 

•919 

•914 

•908 

•903 

291 

•964 

•959 

•954 

•949 

•944 

•939 

•933 

•928 

•923 

•917 

•911 

•906 

292 

•968 

•963 

•958 

•952 

•947 

•942 

•937 

•931 

•926 

•920 

•914 

•909 

293 

•971 

•966 

•961 

•956 

•950 

•945 

•940 

•935 

•929 

•923 

•918 

•912 

294 

•975 

•969 

•964 

•959 

•954 

•949 

.-943 

•938 

•932 

•927 

•921 

•915 

295 

•978 

•973 

•968 

•962 

•957 

•952 

•947 

•941 

•936 

•930 

•924 

•919 

296 

•981 

•976 

•971 

•966 

•960 

•955 

•950 

•944 

•939 

•933 

•927 

•922 

297 

•985 

•980 

•974 

•969 

•964 

•959 

•953 

•948 

•942 

•937 

•931 

•925 

298 

•988 

•983 

•978 

•972 

•967 

•962 

•957 

•951 

•946 

•940 

•934 

•928 

299 

•991 

•986 

•981 

•976 

•970 

•965 

•960 

•954 

•949 

•943 

•937 

•932 

300 

•995 

•990 

•985 

•979 

•974 

•968 

•963 

•958 

•952 

•946 

•941 

•935 

301 

•998 

•993 

•988 

•983 

•977 

•972 

•966 

•961 

•955 

•950 

•944 

•938 

302 

1-002 

•996 

•991 

•986 

•980 

•975 

•970 

•964 

•959 

•953 

•947 

•941 

303 

1-005 

1-000 

•995 

•989 

•984 

•978 

•973 

•968 

•962 

•956 

•950 

•945 

804 

1-008 

1-003 

•998 

•993 

•987 

•982 

•976 

•971 

•965 

•959 

•954 

•948 

305 

1-012 

1-006 

1-001 

•996 

•990 

•985 

•980 

•974 

•969 

•963 

•957 

•951 

306 

1-015 

1-010 

1-005 

•999 

•994 

•988 

•983 

•977 

•972 

•966 

•960 

•954 

307 

1-018 

1-013 

1-008 

1-003 

•997 

•992 

•986 

•981 

•975 

•969 

•963 

•957 

308 

1-022 

1-017 

1-011 

1-006 

1-000 

•995 

•990 

•984 

•978 

•972 

•967 

•961 

309 

1-025 

1-020 

1-015 

1-009 

1-004 

•!98 

•993 

•987 

•982 

•976 

•970 

•964 

310 

1-029 

1-023 

1-018 

1-013 

1-007 

1-002 

•996 

•991 

•985 

•979 

•973 

•967 

17'6.4J^,""  '  ^'  where  h  is  the  height  of  the  barometer  in  inches,  t  the 


at  t°.    If  v  is  any  volume  at  t°  and  h  inches  pressure  and  V  the  corresponding 
pressure,  V  =  v  n. 


428 


GAS  ENGINEER'S  POCKET-BOOK. 
APPENDIX  H. 


Test  for  Sulphuretted  Hydrogen^ 

The  apparatus  represented  by  Fig.  12  consists  of  a  plate  with  a 
circular  channel  half  filled  with  mercury  in  which  rests  a  bell-glass, 
held  down  in  position  by  an  arm  and  cap  not  shown  in  the  figure.  A 
central  tube  connected  below  with  the  gas-inlet  rises  nearly  to  the 
top  of  the  bell-glass,  and  carries  midway  wires  pointed  and  curved  at 
the  end,  from  each  of  which  a  slip  of  lead-paper  hangs. 


OBD 


Fig.  12. 

A  second  pipe  passing  through  the  plate  and  terminating  above  in  a 
short  elbow  provides  an  outlet  for  the  gas,  which  is  burnt  as  it  issues 
from  a  governor  burner  passing  gas  at  about  the  rate  of  five  cubic  feet 
per  hour 

APPENDIX  K. 
Sulphur  Ibst. 

The  apparatus  to  be  employed  is  represented  by  Fig.  13,  and  is  of 
the  following  description : — The  gas  is  burnt  in  a  small  Bunsen 
burner  with  a  steatite  top,  which  is  mounted  on  a  short  cylindrical 
stand,  perforated  with  holes  for  the  admission  of  air,  and  having  on 
its  upper  surface,  which  is  also  perforated,  a  deep  circular  channel  to 
receive  the  wide  end  ot  a  glass  trumpet-tube.  There  are  both^in  the 
side  and  in  the  top  of  this  stand  fourteen  holes  of  five  millimeters 
in  diameter,  or  an  equivalent  air-way.  On  the  top  of  the  stand, 
between  the  narrow  stem  of  the  burner  and  the  surrounding  glass 


ILLUMINATING   POWER   AND    PURITY   OP   GAS. 


429 


trumpet-tube,  are  to  be  placed  pieces  of  commercial  sesqui-carbonate 
of  ammonia  weighing  in  all  about  two  ounces. 

The  products  both  of  the  combustion  of  the  gas  and  of  the  gradual 
volatilisation  of  the  ammonia  salt  go  upwards  through  the  trumpet- 
tube  into  a  vertical  glass  cylinder  with  a  tubulure  near  the  bottom, 
and  drawn  in  at  a  point  above  this  to  about  half  its  diameter.  From 
the  contracted  part  to  the  top  the  cylinder  is  packed  with  balls  of 
glass  about  fifteen  millimeters  in  diameter,  to  break  up  the  current 
and  promote  condensation.  From  the  top  of  this  condenser  there 
proceeds  a  long  glass  pipe  or  chimney 
slightly  bent  over  at  the  upper  end, 
serving  to  effect  some  further  conden- 
sation, as  well  as  to  regulate  the 
draught  and  afford  an  exit  for  the 
uncondensable  gases.  In  the  bottom 
of  the  condenser  is  fixed  a  small  glass 
tube,  through  which  the  liquid  formed 
during  the  testing  drops  into  a  flask 
placed  beneath. 

The  following  cautions  are  to  be 
observed  in  selecting  and  setting  up 
the  apparatus : — 

See  that  the  inlet-pipe  fits  gas-tight 
into  the  burner,  and  that  the  holes  in 
the  circular  stand  are  clear.  If  the 
burner  gives  a  luminous  flame,  remove 
the  top  piece,  and  having  hammered 
down  gently  the  nozzle  of  soft  metal, 
perforate  it  afresh,  making  as  small  a 
hole  as  will  give  passage  to  two-thirds 
of  a  cubic  foot  of  gas  per  hour  at  a 
convenient  pressure. 

See  that  the  tubulure  of  the  con- 
denser has  an  internal  diameter  of  not 
less  than  18  millimeters,  and  that  its 


Fig.  13. 


outside  is  smooth  and  of  the  same  size  as  the  small  end  of  the 
trumpet- tube  ;  also  that  the  internal  diameter  of  the  contracted  part 
is  not  less  than  30  millimeters. 

See  that  the  short  piece  of  india-rubber  pipe  fits  tightly  both  to 
the  trumpet-tube  and  to  the  tubulure  of  the  condenser. 

The  small  tube  at  the  bottom  of  the  condenser  should  have  its 
lower  end  contracted,  so  that  when  in  use  it  may  be  closed  by  a  drop 
of  water. 

The  india-rubber  pipe  at  the  lower  end  of  the  chimney-tube  should 
fit  into  or  over,  and  not  simply  rest  upon,  the  mouth  of  the  condenser. 

A  central  hole,  about  50  millimeters  in  diameter,  may  with  advan- 
tage be  made  in  the  shelf  of  the  stand.  If  a  beaker  is  kept  on  the 
table  below,  the  liquid  will  still  be  preserved  if  by  any  accident  the 
flask  is  not  in  its  place. 


430  GAS  ENGINEER'S  POCKET-BOOK. 

APPENDIX  L. 
The  Gas  Caloj-imeter. 

The  gas  calorimeter,  which  has  been  designed  by  Mr.  Boys,  is 
shown  m  vertical  section  in  Fig.  14.  It  consists,  of  three  parts,  which 
may  be  separated,  or  which,  if  not  in  position,  may  be  turned  rela- 
tively to  one  another  about  their  common  axis.  The  parts  are  (1)  the 
base  A,  carrying  a  pair  of  burners  B,  and  a  regulating  tap.  The 
upper  surface  of  the  base  is  covered  with  a  bright  metal  plate  held  in 
place  by  three  centering  and  lifting  blocks  C.  The  blocks  are  so 
placed  as  to  carry  (2)  the  vessel  D  which  is  provided  with  a  central 
copper  chimney  E  and  a  condensed  water  outlet  F.  Besting  upon 
the  rim  of  the  vessel  D  are  (3)  the  water  circulating  system  of  the 
calorimeter  attached  to  the  lid  G.  Beginning  at  the  centre  where 
the  outflow  is  situated  there  is  a  brass  box  which  acts  as  a  tem- 
perature equalising  chamber  for  the  outlet  water.  Two  dished 
plates  of  thin  brass  K  K  are  held  in  place  by  three  scrolls  of  thin 
brass  L  L  L.  These  are  simply  strips  bent*ouud  like  unwound  clock 
springs,  so  as  to  guide  the  water  in  a  spiral  direction  inwards,  then 
outwards  and  then  inwards  again  to  the  outlet.  The  lower  or  pendent 
portion  of  this  box  is  kept  cool  by  circulating  water,  the  channel  for 
which  may  be  made  in  the  solid  metal,  as  shown,  on  the  right  side,  or 
by  sweating  on  a  tube  as  shown  on  the  left.  Connected  to  the  water 
channel  atlhe  lowest  point  by  a  union  are  five  or  six  turns  of  copper 
pipe  such  as  is  used  in  a  motor-car  radiator  of  the  kind  known  as 
Clarkson's.  In  this  a  helix  of  copper  wire  threaded  with  copper  wire 
is  wound  round  the  tube,  and  the  whole  is  sweated  together  by  immer- 
sion in  a  bath  of  melted  solder.  A  second  coil  of  pipe  of  similar  con- 
struction surrounding  the  first  is  fastened  to  it  at  the  lower  end  by  a 
union.  This  terminates  at  the  upper  end  in  a  block,  to  which  the 
inlet  water  box  and  thermometer  holder  are  secured  by  a  union  as 
shown  at  0.  An  outlet  water  box  P  and  thermometer  holder  are 
similarly  secured  above  the  equalising  chamber  H.  The  lowest  turns 
of  the  two  coils  M  N  are  immersed  in  the  water  which  in  the  first 
instance  is  put  into  the  vessel  D. 

Between  the  outer  and  inner  coils  M  N  is  placed  a  brattice  Q  made 
of  thin  sheet  brass,  containing  cork  dust  to  act  as  a  heat  insulator. 
The  upper  annular  space  in  the  brattice  is  closed  by  a  wooden  ring, 
and  that  end  is  immersed  in  melted  rosin  and  beeswax  cement  to 
protect  it  from  any  moisture  which  might  condense  upon  it.  The 
brattice  is  carried  by  an  internal  flange  which  rests  upon  the  lower 
edge  of  the  casting  H.  A  cylindrical  wall  of  thin  sheet  brass,  a  very 
little  smaller  than  the  vessel  D,  is  secured  to  the  lid  so  that  when  the 
instrument  is  lifted  out  of  the  vessel  and  placed  upon  the  table,  the 
coils  are  protected  from  injury.  The  narrow  air  space  between  this 
and  the  vessel  D  also  serves  to  prevent  interchange  of  heat  between 
the  calorimeter  and  the  air  of  the  room. 

The  two  thermometers  for  reading  the  water  temperatures  and  a 
third  for  reading  the  temperature  of  the  outlet  air  are  all  near 
together  and  at  the  same  level.  ^The  lid  may  be  turned  round  into 
any  position  relatively  to  the  gas  inlet  and  condensed  water  drip  that 


ILLUMINATING   POWER   AND    PURITY    OF    GAS.  431 


432  GAS  ENGINEER'S  POCKET-BOOK. 

may  be  convenient  for  observation,  and  the  inlet  and  outlet  water 
boxes  may  themselves  be  turned  so  that  their  branch  tubes  point  in 
any  direction. 

A  regular  supply  of  water  is  maintained  by  connecting  one  of  the 
two  outer  pipes  of  the  overflow  funnel  to  a  small  tap  over  the  sink. 
The  overflow  funnel  is  fastened  to  the  wall  about  one  metre  above 
the  sink  and  the  other  outer  pipe  is  connected  to  a  tube  in  which 
there  is  a  diaphragm  with  a  hole  about  2'3  mm.  in  diameter.  This 
tube  is  connected  to  the  inlet  pipe  of  the  calorimeter.  A  piece  of 
stiff  rubber  pipe  long  enough  to  carry  the  outflow  water  clear  of  the 
calorimeter  is  slipped  on  to  the  outflow  branch  and  the  water  is  turned 
on  so  that  little  escapes  by  the  middle  pipe  of  the  overflow  funnel, 
and  is  led  by  a  third  piece  of  tube  into  the  sink.  The  amount  of 
water  that  passes  through  the  calorimeter  in  four  minutes  should  be 
sufficient  to  fill  the  graduated  vessel  shown  in  Fig.  16  to  some  point 
above  the  lowest  division,  but  insufficient  in  five  minutes  to  come 
above  the  highest  division.  If  this  is  not  found  to  be  the  case,  a 
moderate  lowering  of  the  overflow  funnel  or  reaming  out  of  the 
hole  in  the  diaphragm  will  make  it  so.  The  overflow  funnel  should 
be  provided  with  a  lid  to  keep  out  dust. 

The  thermometers  for  reading  the  temperature  of  the  inlet  and 
outlet  water  should  be  divided  on  the  centigrade  scale  into  tenths 
of  a  degree,  and  they  should  be  provided  with  reading  lenses  and 
pointers,  that  will  slide  upon  them.  The  them  ometcrs  are  held  in 
place  by  corks  fitting  the  inlet  and  outlet  water  boxes.  The  positions 
of  these  thermometers  should  be  interchanged  every  month.  The 
thermometers  for  reading  the  temperature  of  the  air  near  the  instru- 
ment and  of  the  effluent  gas  should  be  divided  on  the  centigrade  scale 
into  degrees. 

The  flow  of  air  to  the  burners  is  determined  by  the  degree  to 
which  the  passage  is  restricted  at  the  inlet  and  at  the  outlet.  The 
blocks  C  which  determine  the  restriction  at  the  inlet  are  made  of 
metal  ^  inch  or  about  5  millimeters  thick,  while  the  holes  round  the 
lid  which  determine  the  restriction  at  the  outlet  are  five  in  number 
and  are  |ths  inch  or  16  millimeters  in  diameter.  The  thermometer 
used  for  finding  the  temperature  of  the  effluent  gas  is  held  by  a  cork 
in  the  sixth  hole  in  the  lid  so  that  the  bulb  is  just  above  the  upper 
coil  of  pipe. 

The  calorimeter  should  stand  on  a  table  by  the  side  of  a  sink  so  that 
the  condensed  water  and  hot  water  outlets  overhang  and  deliver  into 
the  sink.  A  piece  of  india-rubber  tube  reaching  nearly  to  the  base 
should  be  attached  to  the  waste  water-pipe,  so  as  to  avoid  splashing, 
and  another  piece  may  conveniently  be  slipped  on  to  the  condensed 
water  outlet  so  as  to  lead  the  condensed  water  into  a  flask,  but  care 
should  be  taken  that  the  small  side  hole  is  not  covered  by  the  tube. 
A  glass  vessel  must  be  provided  of  the  size  of  the  vessel  D  containing 
water  in  which  is  dissolved  sufficient  carbonate  of  soda  to  make  it 
definitely  alkaline.  The  calorimeter  after  use  is  to  be  lifted  out  of 
its  vessel  D  and  placed  in  the  alkaline  solution  and  there  left  until  it 
is  again  required  for  use.  The  liquid  should  not,  when  the  calorimeter 
is  placed  in  it,  come  within  two  inches  of  the  top  of  the  vessel.  The 


ILLUMINATING   POWER   AND   PURITY   OF   GAS.  433 

liquid  must  be  replenished  from  to  time,  and  its  alkalinity  must  be 
maintained. 


•l«bo 


c-  Mil-  1,1  METRt  5  . 


a.E. 


Fig.  16. 


F  P 


434 


GAS  ENGINEERS  POCKET-BOOK. 


CALORIFIC  POWER  OP  GAS. 

ifORM  WITH  EXAMPLE  OF   CALCULATION   (see  p.   418), 

Water.  Air. 


Inlet.            Outlet.        Inlet.     Outlet.     4  minutes  2  seconds  =  242 
8'45°  0.        33-22°  C.      15°  C.     12°  C.                      seconds. 
•23            One-sixth  difference  =  0'5. 
•23 
•23            Barometer,  29'9  inches    ...1         Tabular 
8-46                  -21            Meter  thermometer,  60°  F.  )    number  =  -997. 
•22 

•  OQ 

•23            Water  collected,  2-080  litres. 
._                   .p?            Condensed    water    in    20    minutes  = 
1200  seconds,  40-3  c.c. 
•22 
•21 

.no 

8-47                   '24            Log.        24-77 

=  1-3939 

8-46                   '24            Log.         3 

=    -4771 

•24            Log.         2-080 

=    -32W 

5)    3-41 

2-1891 

3)     -682            Log.          -997 

=  1-9987 

33-23            Log.     155-0 

8-46 
Subtract  0-5 

=  2-J004 
=   Gross  calorific  power. 

—                         154-5 

Log.        40-3  =     1-605 
Log.        242    =     2-384 

Log.    1200 
Log.     -997 

=  3-079 
=  1-999 

Log.        1-86  =       -270 

3-078 

Gross    154-5          3-Q78 

Log..       15-2  =     1-181 

139-3  =  Net  calorific  power. 

ILLUMINATING   POWER   AND   PUllITtf    OF    GAS. 


GAS  REFEREES'   STANDARD 
BURNER. 

(Applicable  to  the  Old 
^Regulations.) 

The  burner  which  has  been  adopted  as 
the  Standard  Burner  for  testing  gas  was 
designed  by  Mr.  Sugg,  and  was  called  by 
him  "  Sugg's  London  Argand,  No.  1." 

A  half-sized  section  is  appended,  in 
which  A  represents  a  supply  pipe,  B  the 
gallery,  C  the  cone,  D  the  steatite  chamber, 
E  the  chimney. 

The  following  are  the  dimensions  of 
those  parts  of  the  burner  upon  which  its 
action  depends  : — 

Inch. 

Diameter  of  supply  pipes  .     .     .    0'08 
External   diameter   of  annular 

steatite  chamber 0*84 

Internal  diameter  of  do.    .     .     .     0'48 

Number  of  holes 24 

Diameter  of  each  hole  ....     0'045 
Internal  diameter  of  cone  : — 

At  the  bottom 1-5 

At  the  top 1-08 

Height  of  upper  surface  of  cone 
and  of  steatite  chamber  above 

floor  of  gallery 0-75 

Height  of  glass  chimney    ...    6 
Internal  diameter  of  chimney    .     1'875 


FF2 


436 


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GAS    ENGINEER  S    POCKET-BOOK. 


0-2 


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S  x 


When  O'Connor's  test  meter  is  not  used. 


GLOSSARY    OF    TERMS. 


437 


GLOSSARY   OF   TEEMS   IN   USE  IN    GASWORKS. 

(Sugg.) 


English. 

French. 

German. 

Air. 

Air. 

Luft. 

Ash. 

Cendre. 

Asche. 

Bisulphide  of  carbon. 

Bisulphure  de  car- 

Doppelt  Schwefelkoh- 

bone. 

leustoff. 

Burner. 

Bee. 

Brenner. 

Candle. 

Bougie. 

Kerze. 

Cannel. 

Cannelcoal. 

Kannelkohle. 

Carbon  di-oxide. 

Acide  carbonique. 

Kohlensauer. 

Carbon  mon-oxide. 

Oxyde  de  carbone. 

Kohlenoxyd. 

Cast  iron. 

Fer  fonte. 

Gusseisen  Roheisen. 

Cement. 

Ciment. 

Cement. 

Chimney  (lamp}. 

Cheminee  verre. 

Lampenglas. 

Clay. 

Argile. 

Thon. 

Coal. 

Houille  charbon. 

Steinkohle. 

Coke. 

Coke. 

Coke. 

Exhauster. 

Extracteur. 

Auszicher. 

Fire  brick. 

Brique  refractaire. 

Chamottestein. 

Fire  clay. 

Argile 

Chamotte. 

Gas  fittings. 

Appareils  a  gaz. 

Gaseinrichtung. 

Gasholder. 

Gazometre. 

Gasbehalter. 

Gasholder  curb. 

Corniere. 

Gas  kitchener. 

Cuisiniere  a  gaz. 

Gas  -  kock  und  Brat- 

Herd. 

Gas  main. 

Tuyau  a  gaz. 

Strassengasrohr. 

Gas  pipe. 

Conduit  a  gaz. 

Gasrohr. 

Gas  stove. 

Fourneau  a  gaz. 

Gasofeu. 

Gasworks. 

Usine  a  gaz. 

Gasaustalt, 

Hydrogen. 

Hydrogene. 

Wasserstoff. 

Inlet  pipe. 

Tuyau  d'  entree. 

Einflussrohr. 

Iron. 

Fer. 

Eisen. 

Lamp. 

Lampe. 

Lamp. 

Lime. 

Chaux. 

Kalk. 

Marsh  gas  (methane). 

Gaz  de  marais. 

Sumpfgas-Griibengas. 

Meter. 

Compteur. 

Gasuhr. 

Nitrogen. 

Azote. 

Stickstoff. 

Outlet. 

Sortie. 

Ausfluss. 

Oxide  of  iron. 

Oxyde  de  fer. 

Eisenoxyd. 

Oxygen. 

Oxygene. 

Sauerstoff. 

Pitch. 

Brai. 

Pech. 

Pressure  register. 

Mouchard. 

Retort. 

Cornue. 

Retorte. 

438 


GAS  ENGINEER'S  POCKET-BOOK. 


Glossary  of  Terms  in  Use  in  Gasworks.    (Sugg.)  —  continued. 

English. 

French. 

German. 

Shade. 

Abat-jour. 

Lichtschirm. 

Sheet  iron. 

Tole. 

Schwarzes  Bleoh. 

Sperm  candle. 

Bougie  de  spermaceti. 

Walrathlight. 

Sperm  oil. 

Huile  de  baleine. 

Walrathoel. 

Standard  light. 

Etalon  photometriquc. 

Normallicht. 

Steam. 

Vapeur. 

Dampf. 

Steel. 

Acier. 

Stahl. 

Stop-cock. 

Robinet. 

Hahn. 

Sulphur. 

Soufre. 

Schwefel. 

Sulphuretted   hydro-1 

Hydrogene  sulf  ur6. 

Schwefelwasserstoff. 

gen. 
TaUow. 

Suif. 

Talg. 

Tap. 

Robinet. 

Hahn. 

Tar. 

Goudron. 

Theer. 

Valve. 

Valve. 

Ventil. 

Water. 

Eau. 

Wasser. 

Wax. 

Cire. 

Wachs. 

Wood. 

Bois. 

Holz. 

Wrought  iron. 

Fer  battu. 

Abschlageisen. 

INDEX. 


A  BSORBTNG  hydrocarbons,  326 
J\.    Absorptive  power  of  solids,  339 

1 lime,  278,  372 

water,  196,  374 

Absorption  of  coke,  232 

heat  by  air,  243 

light  by  globes,  309 

Weldon  mud,  274 

Abutments  of  arches,  143 
Accumulator  ram,  friction  of,  151 
Acetate  of  lead  test  papers,  to  prepare, 

342 
Acetylene  absorbed  by  water,  391 

and  air,  390 

iron  burners,  391 

,   description  of,  391 

explosive  mixtures,  391 

'     for  gas  engines,  390 

,    illuminating  value  of,  353 

in  coal  gas,  391 

lighting  power  of,  391 
quantity  from  carbide,  391 
testing  for,  378 
toxicity  of,  391 

value  as  enricher,  390 

under  pressure,  391 

Acid  in  scrubbers,  263 

,  standard  solution  of,  343 

,  10  per  cent,  specific  gravity  of,  375 

Action  in  sulphided  lime  purifiers,  273 

of  lime  on  H2S,  272 

oxide  on  HaS,  269 

Admitting  air  in  third  purifier,  275 
Advantages  of  tar  firing,  242 

turned  and  bored  pipes, 

292 

Aggregate  for  concrete,  73 
Air  and  acetylene,  390 

—  blast  for  water  gas,  393 

—  carburetted  with  tar,  275 

—  compression,  246 
— ,  dry,  weight  of,  328 

— ,  effect  on  illuminating  power,  244 
— ,  flow  of,  in  pipes,  281 

—  for  removing  bad  smell  from  lime,  274 

—  in  purification,  274 


Air  in  smith's  forge,  229 

sulphided  purifier,  275 

— ,  liquid,  density  of,  328 
— ,  pressures  of,  323 

—   required  for  combustion  of  coal,  316 ; 
of  other  fuels,  259,  346 

furnaces,  155,   244 


lights,  311 
— ,  specific  heat  of,  241 
— ,  speed  of  sound  in,  328 

—  valves  for  purifiers,  201 

—  vitiated  by  lights,  305 
— ,  Tolume  of  1  lb.,  327 

— ,  with  all  lime  purification,  274 

sulphided  lime,  273 

Weldon  mud,  274 

Alcohol  vapour  in  mains,  302 
Ale  and  beer  measure,  44 
Allport's  waterproof  roofing,  80 
Allowance  for  lap  of  plates,  213 
snow  on  roofs,  79 


for 


waste  on  rivets,  213 

wind  on  roofs,  79 

Alloys,  melting  points  of,  250,  335 
Aluminium,  joining,  229 

American  wire  gauges,  96 

Ammonia  at  outlet  of  scrubbers,  266 

combinations,  264 

gas,  tension  of,  263 

in  crude  gas,  235 

process  of  purification.  201 

removal,  196 

removed  by  scrubbers,  262 

required  for  purification,  263 

test  solutions  of,  843,  344 

,  to  prevent  loss  of,  265 

,  yield  of,  233,  262 

Ammoniacal  liquor,  analysis,  264 

— — ,  contents  of,  263 

on  oxide,  275 

Amount  of  hydrocarbon  for  enriching 

sulphate  from  liquor,  404 

Amyl-acetate  standard,  370 
Analysing  flue  gases,  240 
Analysis  of  ammoniacal  liquor,  26.4 


440 


INDEX. 


Analysis  of  anthracite,  381 

brick-clay,  69 

bog  ore,  267 

carburetted  water  gas,  392 

coal,  250,  380 

coke,  241 

carburetted  water  gas,  395 

Dmas  bricks,  152 

• granite,  76 

heating  gases,  394 

London  gas,  349 

oil  gas  tar,  396 

petroleum,  386 

purified  Lowe  oil  gas,  392 

spent  oxide,  269 

tar,  407 

water  gas,  392,  395 

Weldon  mud,  274 

Andrew's  patent  fuel,  260 
Anemometers,  217 

Angle  irons,  142 

or  steel  struts,  140 

,  purlins,  142 

and  steels,  weight  of,  91,  et  „ 

Angles  of  cutting  tools,  22S 

repose,  62 

Aniline,  to  produce,  409 
Annular  condensers,  164 
Anti-dip  pipes,  160,  254 
Anti-freezing  mixture,  321 
Anthracite  coal,  analysis  of,  381 

for  water  gas,  398 

Apothecaries'  weight,  42 

Aqueous  vapour,  calculating  for,  365 

from  burners,  308 

,  tension,  326 

,  weight  of,  327 

Arc  of  circle,  41 

Arch  pipes,  curves  in,  160 
Arches,  abutments  for,  143 

,  depth  of,  143 

Area  of  condensers,  163 ;    of  flanges  to 


girders,  132  ;  of  foul  main,  160 ;  of 
oval,  41  ;  of  purifiers,  197 ;  of  retort 
houses,  154 ;  of  retort  house  chimneys, 
158 ;  of  roof,  to  calculate,  78 ;  of  seg- 
ment, 41  ;  of  tar  and  liquor  tanks,  165  ; 
of  workshops,  228. 

Areas  covered  by  light,  358 

of  circles,  24 

washers  and  scrubbers,  195 

Argand  burners  for  testing  gas,  367,  425 

,  supply  pipes  to,  308 

,  flames  of,  361 

Argon,  353 

Arrangement  of  flues,  157 

Arrangements  of  purifier  connections,  199 

Ascension  pipes,  jointing,  160 

.temperatures  in,   247, 

254 

,  thickness,  159 

,  to  cure  when  stopped, 


246 


,  weight  of,  160 


Ash  in  coke  for  furnaces,  241 
• from  Newcastle  coal,  251 


Ash,  to  estimate,  881 
Ash-pans,  water  in,  243 
Asphalt  for  roads,  146 
for  tanks,  209 


Asphalted  felt,  80 
Atmosphere,  composition  of,  328 
Atmospheric  condensers,  163 
Atomic  heat,  340 

specific  heat,  336 


Attrition  metal,  99 
Average  yield  of  tar,  407 
Avoiding  loss  in  cupping,  209 
Avoirdupois  weight,  42 
Axle  tests,  149 


BABBITT  metal,  99 
Backing  of  tank  walls,  204 
Balance  holder,  165 
Ballast  burning,  65 
Balloons,  318 

Barometrical  pressure,  correcting  for,  3 
BaSO4  into  grains  sulphur,  383 
Bath  stone  piers,  safe  load  on,  75 

,  weight  of,  76 

Battens,  82 

Batter  of  chimneys,  179 

Beams,  cast-iron,  137 

,  pine,  safe  load  on,  84 

,  pitch  pine,  85 

,  relative  strength  of,  138 

resistance  of,  136 


Bearing  power  of  ground,  202 

surface  for  girders,  132 

Bearings,  span  between,  18:5 
IJeckton  purifying  method,  374 
Beer  measure,  44 
Belting,  leather,  187 

,    preservation  of,  187 

,    strength  of,  188 

Belts,  proportions  of,  188 

,   width  of,  190 

Benches,  covering  for,  154 
.,  tie-rods  for,  154 


Bending  glass  tubes,  324 

— moment  of  standards,  223 

Bends,  dimensions  of,  116 

,  force  tending  to  drive  off,  291 

Benzene  as  an  enricher,  301 

,  boiling  point,  388 

,  compared  with  napthalene,  387 

,  enriching  power  of,  388 

,  <fec.,  dissolving  power  of  water, 

388 

,  freezing  point  of,  388 

from  gas,  388 

in  coal  gas,  325 

,  specific  gravity  of,  388 

,  testing,  390 

-,  vapour  tension  of,  387 


Benzol  as  an  enricher,  388 

dissolving  sulphur,  301 

,  enriching  power  of,  301 

, — ,  stability  of  gas  with,  387 

vapour  retained  by  gas,  301 

Best  heats  for  carbonising,  234 


INDEX. 


441 


Best  heats  for  cooking,  317 
Birmingham  gauges,  96 
Bituminous  coal,  composition  of,  251 
Blast  mains  for  water  gas,  393 
Blocks,  cement,  74 

in  cups  of  gasholders,  224 


Block  tin  tube,  weight  of,  124 
Blowers  for  water  gas,  393 
Blue  flame  at  outlet  of  flue,  242 
Board  of  Trade  regulations  for  bridges, 
138 

thermal  unit,  340 


—  unit  of  electricity,  89 


Boards  for  scrubbers,  195 
Bog  ore,  analysis  of,  267 
Boiled  linseed  oil,  77 
Boilers,  166,  176 

chimney  area  for,  176 

chimneys  for,  176 

designing  data  for,  171 

dimensions  of,  170 

draught  for,  176 

feeding,  260 

fire  grate  area,  173 

flaws  in  plates,  175 

flues  for,  176 

flue  gases,  261 

for  steam  heating,  316 

furnace  tubes,  pressures  on,  174 

horse-power  of,  174 

Lancashire,  173 

losses  in,  169 

overheating,  175 

rivets  for  plates,  175 

proportions  of,  170 

settings  for,  176 

shafts,  settling,  181 

size  of  chimney  for,  178 

steam  pipes  for,  182 

superheaters  for,  176 

to  prevent  incrustations  in,  261 

water  tube,  coke  fired,  175 


Boiling  points,  335 
of  benzene,  388 

enrichers,  386 

ethane,  353 

Bolt  centres  in  angle  irons,  142 
heads,  weight  of,  102 

threads,  Whitworth,  126 

Bolts  and  nuts,  proportions  of,  102 
,  strength  of,  103 

Bond,  English,  70 

,  Flemish,  71 

,  hoop-iron,  67 

Books  damaged  by  gas-light,  801 

Boring  for  tanks,  202 

Box  tinplates,  sizes  and  weights,  97 

Boxing  round  valves,  165 

Boyle's  law,  365 

B.^ys'  calorimeter,  480 

Brake  horse-power,  166 

Brass,  sheet,  weight  of,  124,  130 

Breaking  joint  in  gasholder  sheets,  210 

strength,  101 

weight  on  steel  joists.  188 

Breeze  as  fuel,  282,  242,  317 


Brick-clay,  analysis  of,  69 

columns,  strength  of,  68 

joints,  strength  of,  72 

pillars,  69 

tanks,  205 


Bricks,  cohesive  force  of,  203 

,    Dinas,  analysis  of,  152 

,  good,  to  tell,  69 

quality  of,  67,  69 


Bricklayer's  hod  measurement,  73 
,  work  of,  72 


Brickwork,  66 

•    in  cement,  safe  load  on,  75 

material,  size  of,  67 

,  weight  of,  67 


supporting  retorts,  155 

,  weight  of,  69 

Bridges,  Board  of  Trade  regulations,  138 
,  wrought-iron,  weight  of,  141 


Briquettes,  317 

of  coke  dust,  242 

British  thermal  unit,  166 
Broken  pipe  mending,  292 
Bromine,  to  prepare,  344 
Brown's  gas-making  process,  387 
Buckstaves,  154 
Building  Act,  Metropolis,  72 
chimneys,  158,  181 


Bunsen  burner,  mixing  gas  and  air  in,  312, 
317 

flame  temperature,  357 

Burners,  aqueous  vapour  from,  308 

,  comparative  duty  from,  348 

,  efficiency  of,  848 

of  Dibdin's  standard,  369 

,  number  required,  811 

.products   of  combustion  from, 


tips,  308 


Burning  clay,  65 

of  candles,  correcting  for,  361 


Bursting  force  of  water,  203 

strength  of  boiler  shell,  173 

Bye-pass  to  gasholders,  912 
Bye-passes  in  works,  165,  196 
Bye-passing  condensers.  258 

/BAKING  of  coal,  380 

\J    Calcic  carbide,  pressure  from,  391 

specific  gravity,  391 

for  power,  176 


Calculating  comparative  lights,  359 

horse-powers,  166 

indicated  horse-powers,  169 

roof  areas,  78 

size  of  exhausters,  168 

strength  of  tank  walls,  207 

Calories,  340 

Calorific    power    developed    by     steam 
engines,  191 

of  Dpwson  gas,  317 

value  for  illuminating,  360 

of  carbon,  156 

coal  gas,  840 


—  coke,  260 

—  to  test,  417 


442 

Calorific  value  of  gases,  315 

— — — - — • gas  in  burners,  315 

Calorimeter,  Mahlers's,  249 

>  Boys',  430 

Camber  in  girders,  132 
Candle  balance,  360 

ends  in  photometers,  360 

Candles,  old,  361 

,  per  gallon,  385 

,  standard,  360 

Cannel,  as  an  enricher,  386 
Cantilever  type  gasholders,  223 
Capacities  for  pumps,  185 

of  circulating  tanks,  192 

meters,  321 

scrubbers,  195 

station  meters,  229 

Capacity,  measures  of,  44 

Carbide,  yield  of,  390 

Carbon  atoms  in  enrichers,  301 

bisulphide,  273 

,  calorific  value  of,  156 

di-oxide,  action  of  lime  on,  272 

,    causes  loss  of  light,  347 

- — — ,    description  of,  352 

in  boiler  flues,  261 

water  gas,  394 

,    per  minute  of  run,  395 

produced  by  gases,  331 

lights,  305 

,  reduction  of  illuminating 

power  by,  267 

,  removal  of,  271 

— ,  testing  for,  378 


INDEX. 


escaping  unconsumed,  307 

,  heat  energy  of,  341 

,  units  from,  244 

in  coke,  382 

furnaces,  241 

retorts,  247 

sloping  retorts,  247 

monoxide,  diluting  effect  of,  255 

• ,  water  in,  394 

Carbonic  acid,  effect  on  rabbits,  399 

Carbonising,  233 

at   different   temperatures, 

0<J« 

high  temperatures,  233 


— ,  best  heat  for,  234 

— ,  labour  required  for,  245 

—  tar,  251 


Carburetted  water  gas,  analysis  of,  352, 


399 


,  heating  value  of, 

,  length  of  flame 

with,  399 
Carburetting  air  with  tar  for  purification, 

275 

for  testing,  370 

Carburettor  for  water  gas,  393 
Carb-irine,  condensation  with,  402 

' ,  quantity  required,  386 

,  retained  by  gas,  386 

Carcel  standard,  370 
Care  of  gasholders,  279 


Carriages  to  gasholders,  224 
Carrying  capacity  of  pipes,  285 
Case  hardening,  100 
Cast-iron  beams,  99,  137 

columns  for  gasholders,  210 

girders,  138 

pipes,  coating  for,  123 

• ,    weight  of,  114,  281 

as  girders,  144 


Casting  pipes,  288 

Castings,  contraction  of,  99,  229 

Catch  purifiers,  271 

Cause  of  napthalene,  301 

Caustic  lime,  to  test,  372 

Ceiling,  reflecting  power  of,  307 

Cement  and  sand,  strength  of,  72 

blocks,  74 

bricks,  strength  of,  68 


,  coefficient;  of  expansion  of,  74 

for  repairing  pipes,  292 

—  rust  joint,  127 


-,  Portland,  use  of,  73 
-,  Roman,  74 


Chains,  equilibration,  for  gasholders,  211 

,  notes  on,  111 

,  strengths  of,  109 

Chalk,  lime  made  from,  270 
,  value  of,  270 


Changes  of  wood  to  coal,  381 
Channel  iron  curbs,  224 
Charcoal,  wood,  gas  from,  252 
Charges,  deep,  233 

6-hour,  and  4-hour,  238 


Charging,  heat  lost  during,  244 

,   time  required,  246 

unevenly,  233 

Charles'  law,  332,  365 

Cheapest  curb,  213 

Check  purifiers,  271 

Checker  work  in  water  gas  plant,  394 

Chimney  area  for  boilers,  176 

as  ventilating  flue,  308 

dimensions,  177 


Chimneys,  batter  of,  179 

,  Board  of  Works  rule,  17 

,  building  notes,  181 

,  coal  consumption,  178 

,  division  walls  in,  158 

,  draught  in, 158 

,  power  of,  1 70 


,  fire-brick  lining  to,  179 

for  boilers,  176 

products  works,  404 

,  heat  at  exit  of,  181,  261 

,  lightning  conductors  for,  159 

near  buildings,  158 

,  proportion,  177 

,  retort  house,  158 

,  vacuum  in,  159 

,  velocity  of  gases  in,  179 

,  wind  pressures  on,  179 

Circle,  arc  of,  41 

,    properties  of,  41 

Circles,  areas  of,  24 

,  circumferences  of,  24 

Circular  retorts,  155 


INDEX. 


443 


Circular  saws,  rate  of,  228 
Circulating  tanks,  capacities  of,  192 
Circumferences  of  circles,  24 
Glaus  process  of  purification,  201 
Clay  burning,  65 

for  bricks,  analysis  of,  69 

,  safe  load  on,  75 

retorts,  155 

,  gas  lost  from,  244 

,  life  of,  223 

Clearing  napthalene    from     condensers, 

256 

Climatic  effects  on  distillation,  239 
Clinkering,  243 
Clinkers  in  concrete,  209 
Coal,  analysis  of,  250 

,  bituminous,  analysis  of,  380 

,  calorific  power  of,  342 

consumed  by  chimneys,  178 

,  consumption  of,  in  trains,  232 

,  conversion  on  carbonising,  251 

dust  in  air,  329 

,  evaporative  power  of,  176 

,  experiments  on,  382 

,  exposed  to  air,  231 

gas,  acetylene  in,  391 

compared  with  Dowson  gas,  400 

,  loss  by  compression,  403 

,  refrigerated,  401 

handled  by  stokers,  246 

,  igniting  point  of,  232 

,  measurement  of,  145 

,  moisture  in,  251 

,  nitrogen  in,  265 

,  per-centage  of,  in  use,  250 

,  products  of  distillation,  235 

,  required  in  furnaces,  244 

,  soot  from,  317 

,  space  occupied  by,  145 

,  to  obtain  specific  gravity  of,  380 

stacking,  231 

storage,  145 

,     tie-rods  in,  146 

stores,  notes  on,  148 

tar  constituents,  400 

distillates,  406 

testing,  381 

,  to  ascertain  if  good,  252 

used  to  fire  retorts,  239 

,  various,  weight  of,  145 

,  ventilation  of,  145 

Coating  for  gasholders,  280 

pipes,  123,  291 

service  pipes,  292 

Cochineal,  to  prepare,  343 
Coefficient  of  expansion  of  cement,  74 
— — gases,  332 

metals,  334 


friction,  186 
linear  expansion,  89 


Cohesive  force  of  bricks,  203 

resistance  of  tank  walls,  203 

Coke,  absorption  of,  232 

,  analysis  of,  241 

——    breaker,  breeze  from,  232 


Coke,  contents  of,  244,  382 

drawn  easily,  244 

fired  water  tube  boilers,  175 

for  boiler  in  water  gas  plant,  398 

Dowson  gas,  401 

furnaces,  ash  in,  241 

generator,  394 


from  Peebles  process,  402 

,   hard,  to  obtain,  244 

in  scrubbers,  195 

,    measurement  of,  145 

,    moisture  in,  244 

,   organic  matter  in,  243 

removed  by  conveyor,  155 

stacking,  232 

,   to  estimate,  381 

used  to  fire  retorts,  239 

,  water  required  to  slake,  244 

,   weight  of,  145 

,  yield  of,  244 

Collapsing  pressure  of  boiler  tubes,  173 
Colour  of  gas  purified  by  oxide,  268 

test,  Harcourt's,  376 

Coloured  lights,  311 
Colours  for  drawings,  60 

of  different  temperatures,  248 

Columns,  gasholder,. strength  of,  222 

of  brick,  strength  of,  68 

resistance  of,  223 


Combination  of  nitrogen  in  coal,  384 
Combining  effect  of  ammonia,  263 

equivalents  of  ammonia  and 


sulphuric  acid,  404 

power  of  oxide,  268 

weights  of  elements,  322 

Combustion,  conversion  of  sulphur  on, 

382 

• ,  gaseous  products  from,  346 

or  fuels,  259 

air  or  oxygen  re- 


temperature   of, 


quired,  259,  305 

gases, 

332 


,  oxygen  required  to  support, 


,  products  of,  356 

-,  to  find  heat  of,  347 


Commercial  benzol,  389 

Comparative  cost  of  different  lights,  313 

duty  of  burners,  348 

pressures,  299 

prices  of  French  and  English 


gases,  304 


strengths  of  metals,  130 
weights  of  metals,  128 
Comparison  of  engines,  401 

Weldon  mud  and  oxide,  274 

wind  pressures  on  circular 

objects,  219 

Composite  pipe,  weight  of,  123 
Composition  of  cast  iron,  99 

fire-clay,  152 

fuels,  382 

—  gas  after  scrubbers,  266 

— — at  different  heats,  20? 


444 


INDEX. 


Composition  of  natural  gas,  851 

producer  gases,  241 

purified  gas,  277 

. the  atmosphere,  328 

Van  Steenburg  gas,  400 

water  gas,  351 

Compressed  air,  246 

in  retort  houses,  154 

Compressing  coal  gas,  403 
Compression,  contraction  of  iron  by,  213 

in  gas  engines,  190 

of  earths  by  head  of  water, 


207 


generator  gas,  401 

Pintsch  gas,  402 

strains  in  curbs,  224 


Concrete,  65 

aggregate  for,  73 

clinker  in,  209 

fire-bricks  in,  209 

mixing,  73,  209 

strength  of,  75 

tanks  with  iron  bands,  207 

volume  of  spaces  in,  74 

water  required  for,  74 

water-tight,  207 
Condensation,  effect  of,  255 

.  of  steam,  182 

,  speed  of,  164 

under  pressure,  165 

with  carburine,  402 

Condensed  gas,  impurities  in,  256 
Condensers,  163 

,    areas  of,  163 

,    best  temperature  for,  255 

,    bye-passing,  258 

,     doing  without,  255 

for  water  gas,  393 

in  sulphate  plant,  404 

,    loss  of  heat  in,  164 

mains,  fall  in,  165 

,    temperatures  in,  254 

,    valves  for,  164 

Condensable  vapours  in  hydraulic  mains, 

254 
Condensing,  255 

• acetylene,  391 

below  60°  P.,  256 

— thoroughly  before  scrubbers, 

255 

water  gas,  306,  396 

Conducting  power  of  solids,  338 
Conductors,  lightning,  181 
Connecting  services,  296 
Connections,  bye-passes  to,  196 

,  dimensions  of,  116 

,  finding  leaks  in,  194 

for  pumps,  184 

in  works,  size  of,  162 

— to  purifiers,  198 

,  weight  of,  116 

Constant  level  water  gauges  for  station 

meters,  319 

Constituents  of  coal  tar,  406 
Construction  of  purifiers,  198 
Consumption  in  gas  engines,  193 


Consumption  per  head,  151 

of  coal  in  trains,  232 

fuel  per  I.H.P.,  176 

gas  per  head,  319 


Contact  of  gas  with  water,  279 
Contents  of  ammoniacal  liquor,  263 
pipes,  90,  281 


Continuous  girders,  139 
Contraction  of  castings,  99,  229 

holders  on  rising,  226 

iron  by  compression,  213 


Conversion  of  coal  on  carbonising,  251 
sulphur  on  combustion, 


Converting  per  cent,  to  cubic  inches  per 

gallon,  378 

Conveyor,  saving  by,  152 
Cooking,  best  heats  for,  317 

,  gas  required  for,  314 


Cooling  gas  engines,  192 

excessively,  255 

surfaces  for  condensing,  163 


Coping,  72 

Copper,  expansion  of,  213 

nails,  weight  of,  98 

pipes,  weight  of,  124 


Cork  refuse,  gas  made  from,  253 
Corners  in  English  bond,  70 

Flemish  bond,  71 

Cornish  boilers,  proportions  of,  170 
Correcting  by  tabular  numbers  (diagram), 

368 
for  aqueous  vapour,  365 

barometrical  pressure,  365 

rate  of  burning  of  candles 

•  gas  (dia- 


(diagram),  362  ;  rule,  361 


gram),  364  ;  rule,  363 

temperature,  365 

and.  pressure, 


366 

Corrugated  iron,  weight  of,  98 
Cost  of  brickwork  tank,  203 

enrichment,  385 

fitting  gas  to  railway  carriages, 


402 


gasholders,  210,  219 

metal  tanks,  203 

motors  per  horse-power,  315 

settings,  156 

six-lift  gasholder,  219 

water  gas,  399 


Covering  power  of  paint,  76 

sheet  lead,  96 

varnish,  77 


tar  and  liquor  tanks,  165 

Coverings  to  roofs,  79 

tops  of  benches,  154 


Covers  for  purifiers,  201 

Crane  hooks,  proportions  of,  150 

Cranes,  hydraulic,  151 

Crank  shafts,  diameter  of,  187 

Creosote  oil  for  exhausters,  258 

oripps  on  Pole's  formula,  294 

Croll's  sulphate  plant,  404 

Crown,  radius  of,  225 

sheets,  riveting  to  trussing, 


INDEX. 


445 


Crown  sheets,  thickness  of,  226 

Crowns  of  gasholders,  213 

,  strains  on,  with  different  rises, 


Walker's  rule,  214 


Crude  carburetted  water  gas,  analysis  of, 
395 

gas,  ammonia  in,  235 

residuals  from,  235 

oil,  products  of,  381 

Crushing,  resistance  to,  68 

stress  on  curbs,  227 

Cube  roots,  1 

Cubes,  1 

Cubic  feet  to  cubic  metres,  58 

measure,  44 

metre  gas  in  English  money,  304 

metres  to  cubic  feet,  59 

Cupolas  for  melting  iron,  144 
Cupping,  to  avoid  loss  in,  209 
Cuprous  chloride,  to  prepare,  344 
Cups  and  grips,  224 
Curl ,  best  form  of,  210 

compression  strains  in,  223 

crushing  stress  in,  227 

for  trussed  holders,  210,  213 

steel,  to  gasholder,  211 

weight  of,  244 

Curbs  with  two  angles,  211 

Curves,  elevation  of  outer  rail  on,  149 

in  arch  pipes,  1(30 

• ,    resistance  of,  149 

,    to  set  out,  147 

Cutting  tools,  228 

Cyanides,  best  temperatures  for,  265 

,  reaction  of,  196 

Cyanogen  in  coal  gas,  265,  276 
,   formation  of,  266 

liquor,  Prussian  blue,  384 

,  to  recover,  265 

,  when  produced,  262 

Cylinders,  engine, -thickness  of,  168 

,    expansion  of,  210 

,    hydraulic  thickness  of,  151 

of   wrought  iron    and    steel, 

strength  of,  171 

,    size  of,  to  drive  exhausters,  168 

,    steel,  strength  of,  172 

,   temperatures  in,  168 

Cylindrical  beam,  strength  of,  222 

"PvAMAGE  to  books  by  gas-light,  308 
JL/    Damp  coals,  sulphur  from,  233 
courses,  66 

sand,  resistance  of,  204 

Danger  of  fire  with  liquor  tanks,  165 
Daylight,  power  of,  307 

Dead  loads  in  building,  87 
Deals,  82 

Decagon,  length  of  side  of,  41 
Decimals  of  a  foot,  48 

hundredweight,  46 
—    mile,  47 

pound  weight.  48 

ton.  49 


Decimals  of  a  year,  47 

an  inch,  47 

£1,  45 

Decomposition  by  light,  360 

of  water,  temper atiire  of,  894 

Deep  charges,  233 

Delivery  pipes  for  pumps,  184 

of  high  pressure  gas,  285 

Delta  metal,  99 
Density  of  liquid  air,  328 
Depth  for  pipes,  291 

of  arches,  143 

gas  mains,  279 

lead  in  ordinary  joints,  285 

lifts,  212 

yarn  in  pipe  joints,  292 


Designing  boilers,  171 
Detecting  oxygen  in  coal  gas,  378 
Determining  caking  of  coal,  380 
Diagram  for  correcting  by  tabular  num- 
bers, 368 

for  rate  of  burn- 
ing of  candles,  362  ;  gas,  364 

Harcourt's  colour  test,  377 

of  comparative  prices  of  French 

and  English  gases,  304 

number  of  feet  for  one  penny, 


•  rolled  iron  joists,  134 
-tabular  numbers,  366 
•thickness  of     wrought-iron 

.ipes,  120 

and  pressures  of  gas- 
holders, 221 

•  showing  sulphur  from  BaSOi, 


tanks,  208 


383 
Diagrams  from  gas  engines,  191 

of  distributing  power  of  pipes, 

282 

Diagonal  bracing  to  gasholder  framing, 

210,  220 
Diameter  of  crank  shafts,  187 

exhaust  pipes,  182 

Dibdin's  pentane  burner  dimensions,  371 
standard,  burner  of.  369 

Dies,  228 

Different  temperatures,  colours  of,  248 

Diffusion  of  gases,  279 


Digging,  64 
Dili 


iluting  effect  of  carbon  monoxide,  255 
,  255 


Dimensions  of  bends,  1 

boilers,  170 

chimneys,  177 

-dry  meters,  320 

feed  pumps,  186 


289 


flanged  connections,  118 

pipe  flanges,  289 

pipes,  286 

rack  and  pinion  valves,  293 

socket  joints,  289 

station  meters,  230 

turned  and  bored  pipes, 


•wet  meters,  319 


446 


INDEX. 


Dinas  bricks,  analysis  of,  152 
Dinsmore  process,  gas  made  by,  253 
Dip  pipes,  160 

,   jointing,  160 

Direct  fired  settings,  losses  in,  239 
Discs  for  photometers,  359 
Disillumined  gas  plus  benzene,  302 
Dissolving  napthalene,  301 

in  condensers.,  256 

Distance  apart  of  slating  laths,  79 

for  photometric  standard,  359 

lights  are  visible,  310 

Distillates  from  coal  tar,  406 
Distillation,  fractional,  235 

,    products  of,  381 

,  coal,  235 

Distilling  shale  oil,  385 

tar,  results,  407 

Distortion  of  standards,  223 
Distributing  hydraulic  power,  151 
mains,  292 

power  of  pipes  (diagrams), 


282 


water  in  scrubbers,  195 


Distribution,  281 

of  secondary  air,  157 

District  pressures,  300 
Dividing  a  line,  64 
Division  walls  in  chimneys,  158 
Divisions  of  photometer  bars,  358 
Dodecagon,  length  of  side  of,  41 
Doing  without  condenser,  255 
Dowson  gas,  coke  from,  401 

compared  with  coal  gas,  400 

,  explosive  force  of,  400 

— ,  gasholder  for,  401 
,  heating  value  of,  401 

in  engines,  193 

per  horse-power,  400 

producer  gas,  400 

steam  required  in,  401 


Drains  for  retort  houses,  154 
Draught  for  boilers,  176 

in  chimneys,  158, 117 

power  of  chimneys,  179 

Drawing  coke  early,  244 

paper,  sizes  of,  59 

Drawings,  to  colour,  60 
Drilling  holes  in  mains,  291 
Drills,  speed  of,  228 
Drums  of  station  meters,  230 
Dry  measure,  44 

meters,  particulars  of,  320 

,  tests  of,  321 

Durability  of  water  gas  flame,  399 

test,  357 

Duty  of  various  burners,  306 


E 


ARTH  backing,  resistance  of,  203 
Earths,  natural  slopes  of,  62,  202 
,  weight  of,  62 


Earthy  matters  in  lime,  270 

Effect  of  air  in  purification,  274 

•  carbonic  acid  on  rabbits,  399 


Effect  of  carbonic  acid  on  sulphided  lim« 
purifiers,  273 

cold  on  tower  scrubbers,  262 

condensation,  255 

heat,  247 

on  COa,  235 

H2S,  235 

metals,  114 


heating  to  1,000°,  235 
heavy  gasholders,  212 
H2S  on  sulphided  lime  purifier, 

pressure  on  flames,  356 

meters,  321 

retorts,  244 


radial  rollers,  211 

•  tangential  rollers,  211 

temperature  on  scrubbers,  262 

Effective  heating  duty  of  gas,  341 

pressure  on  pistons,  169 

Efficiency  of  incandescent  burners,  348 
non-conducting  materials, 

182 

oil  engines,  194 

Egner's  method  of  preparing  lime,  271 
Elastic  force  of  aqueous  vapour,  326 

strength,  101 

Elasticity,  modulus  of,  101,  143 
Electric  lamps,  incandescent,  313 
units.  89 


Electrical  conductivity  of  metals,  98 
memoranda,  350 


Electricity  damaging  pipes,  291 

plants,  losses  in,  169 

Elementary  bodies,  322 
Eliminating  power  of  oxide,  268 
Engine  journals,  186 
Engines,  166 

,  coal  required  for,  176 

,  comparison  of,  401 

,  crank  shafts,  187 

,  gas,  190 

,  losses  in,  169 

oil,  194 


English  bond,  70,  72 
Enrichers,  boiling  points  of,  386 

,  sulphur  in,  386 

Enriching  apparatus,  position  for,  402 

power  of  benzene,  301,  388 

Peebles  plant  gas,  40C 

processes,  385 

value  of  oil  gas,  386 

carburetted  water  gas, 


396 
Enrichment,  cost  of,  385 

,  per  gallon,  385 

Equation  of  water  gas  production,  398 
Equilibration  chains  to  gasholders,  214 
Equivalent  liquid  measures,  56 

measures  of  length,  56 

,  mechanical,  of  light,  356 

normal  solutions,  346 

of  heat,  166 


weights,  56 


Escape  of  CO  in  ordinary  furnaces,  242 
Estimating  ash,  381 


INDEX. 


447 


Estimating  coke,  381 

sulphur  in  coal,  381 

temperatures,  249 

Ethane,  boiling  point  of,  353 

,    illuminating  value  of,  353 

Ethine,  description  of,  391 
Ethylene  and  oxygen  mixed,  387 

,  description  of,  352 

,  illuminating  value  of,  353 

Evaporating  with  different   qualities  of 

gas,  356 
Evaporation  of  water,  332 

under  furnaces,  155 


-,  power  of  coal,  259 
fuels,  259 


Evils  of  over-exhausting,  258 
Examining  heat  of  retorts,  234 
Excavating,  64 
Exhaust  from  gas  engines,  401 

pipes,  182 

from  gas  engines,  191 

,  noises 

in,  192 
Exhausters,  166 

,  horse-power  required,  167 

,  lubricating,  258 

,  to  calculate  size  of,  168 

Exhausting,  258 

at  120°  F. ,  258 

,  evils  of  over,  258 

Expansion  and  weight  of  water,  333 

by  heat,  330 

in  steam  pipes,  182 

linear,  coefficients  of,  89 


of  copper,  213 
cyli:   " 


inders,  210 
freezing  water,  337 
gases,  323 

,  coefficient  of,  332 

iron,  213 

and  cement,  209 

by  tension,  213 


liquids,  332 

by  heats,  338 


metals,  coefficients  of,  334 
oxide,  268 


Experiments  on  coal,  382 
Exploding  coal  dust,  329 
Explosions  in  water  gas  plant,  394 

with  acetylene,  391 

petroleum  vapour,  385 

Explosive  mixtures,  191 

— ,  force  of,  329 

,  kindling,  329 

,  limiting,  329 

,  value  of,  193 

power  of  Dowson  gas,  317,  400 

Expulsion  of  burnt  gases  from  gas  engines, 

gases  from  water,  196 

Extension  of  gasholder  space,  210 
Eye,  power  of,  358 

FACING  and  pointing,  74 
Factors  of  safety,  89 
on  stones,  76 


Factory  chimneys,  178 

floors,  loads  on,  82 


Fall  in  condenser  mains,  165 
gutters,  80 


Falling  water,  horse-power  of,  87 
Fall  required  in  mains,  291 
Fastenings  for  purifiers,  200 
Feeding  boilers,  260 
Feed  pumps,  dimensions  of,  186 

water,  heating,  261 

Feet  for  Id  (diagram),  303 
Felt  asphalted,  80 

.weight  of,  80 

FeiTocyanide  of  iron,  276 
Finding  leaks  in  connections,  194 

mains,  292 

proportions  of  enriching  gas,  385 


Fire  bars,  thickness  of,  173 
space  between,  155 


Fire-brick  lining  to  chimneys,  179 
Fire-bricks  in  concrete,  209 

,  safe  load  on,  75 

,  test  of,  153 

,  weight  of,  68 

Fire-clay  blocks,  weight  of,  153 

,    composition  of,  152 

,    notes,  153 

,    specific  heat  of,  152 

Fire,  danger  of,  with  liquor  tanks,  165 

Firegrate  area  in  boilers,  173 

Fires,  heats  of,  317 

Firing,  gaseous,  157 

Fittings  for  wrought-iron  tubes,  2i>3 

Fixing  meters,  321 

Flame,  gas,  cause  of  luminosity  in,  355 

temperatures,  354 

Flames,  effects  of  pressure  on,  356 

in  rare  atmospheres,  308 

,  oxygen  required  to  support,  357 

,  theory  of  formation  of,  311 

,  temperatures  of  changes  in,  353 

Flanged  connections,  dimensions  of,  118 
Flanges,  area  of,  to  girders,  132 

•  for  pipes,  dimensions  of,  289 

of  cast-iron  tanks,  203 

, proportions  of,  122 

to  purifiers,  198 

Flat  plates,  strength  of,  143 

pointing,  74 

rolled  iron,  weight  of,  91 

Flaws  in  boiler  plates,  175 

Flemish  bond,  71 

Floor  joists  in  basements,  82 

retort  houses,  154 


Floors,  loads  on,  «- 

,  safe  loads  on,  78 


Flow  of  air  in  pipes,  281 
Flue  gases  in  boilers,  261 

,  proper  proportions  of,  240 


Flues,  arrangement  of,  157 

,    blue  flame  at  outlet  of,  242 

for  boilers,  176 

gas  stoves,  314 

,    size  of,  158 

,    temperatures  in,  154 

,    vacuum  in,  241 


448 


INDEX. 


Flux  for  soldering,  124 
Flywheels,  safe  speed  of,  187 
Fog  in  photometer  rooms,  358 
Footings,  65 

Footpaths  of  tar  concrete,  146 
Force  of  explosive  mixtures,  329 

the  wind,  215 

water  (bursting),  203 

pumps,  186 

tending  to  drive  off  bends,  291 

Forcing  gas  down  mains,  321 
Formation  of  cyanogen  compounds,  266 
Formula,  Pole's,  Cripps  on,  294 

Foot,  decimals  of,  48 
Foul  main,  area  of,  160 

temperature,  160,  254 

Foundations,  64 

for  boilers,  176 

tanks,  202 

in  water,  65 

,  pressures  on,  65 

Fractional  distillation,  235 
Freezing  of  water  in  tanks,  203 
mixtures,  337 

points,  333 

of  benzene,  388 

French  and  English  gases,  comparative 

prices,  304 

words  for  gas  apparatus,  437 

Friction,  co-efficient  of,  186 
in  condensers,  165 

of  accumulator  ram,  151 

to  separate  tar,  159 

Front  walls  to  benches,  155 
Frost,  action  on  mortar,  74 
in  tanks,  279 

Fuel,  Andrew's  patent,  260 

,  composition  of,  382 

,  consumption  per  I.H.P.,  176 

,  depth  of,  157 

,  evaporative  power  of,  259 

in  generators,  393 

of  breeze,  317 

,  petroleum  as,  176 

,  required  for  water  gas,  394 

sulphate  plant,  405 

Fuels,  air  required  for,  346 

• ,    combustion  of,  259 

,    space  over,  155 

,    heating  power  of,  260 

,    temperature  to  convert  to  CO,  240 

Furnace  efficiency,  to  estimate,  155 

flue  seams  for  boilers,  176 

Furnaces,  air  required  in,  155,  240,  244 

C  in,  241 

coal  required  in,  244 

generator,  157 

labour  required  for,  245 

regenerative,  157 

repair  of,  243 

temperature,  to  find,  249 

-T water  evaporated  by,  243 

Fusible  alloys,  melting  points  of,  250 
Fusing  point  of  napthalene,  256 
Fusion,  latent  heats  of,  338 

,  temperatures  of,  250 


GAIN  with  gaseous  fuel,  241 
Galvanised  slate  nails,  96 
Gas,  analysis  of,  349 

and  air  In  burners,  312,  347 

,  benzene  from,  388 

,  carburine  retained  by,  386 

delivery  at  high  pressure,  285 

discharged  through  mains,  rules,  281 

,  effective  heating  duty  of,  341 

engines,  190 

,  acetylene  for,  390 


,  consumption  in,  193 

,  diagrams,  191 

,  exhaust,  401 

•pipes,  191 


for  tramcars,  192 

-,  heat  units  lost  in,  193 


,  horse-power  of,  191 

,  mechanical  efficiency  of,  191 

,  meters  for,  192 

,  pressures  in,  190,  401 

,  scavenging,  193 

,  starting,  193 

,  stopping,  193 

,  thermal  efficiency  of,  166 

— —  enriched  per  gallon  of  oil,  385 

evaporates  gasolene,  402 

flames  for  ventilation,  311 

—  for     motive     power    of     different 
illuminating  powers,  340 

from  condensers,  analysis  of,  256 

iron  and  steam,  380 

wood,  387 

charcoal,  252 


,  heat  units  from,  340 

heating  before  combustion,  308 

,  illuminating   power   of,    given    in 

table,  426 

•  in  gas  stove  flues,  314 

generator  furnaces,  240 

,  lifting  power  of,  318 

,  specific  heat  of,  336 

,  to  obtain  specific  gravity  of,  354 

weight  of,  354 


,  velocity  of,  in  chimneys,  179 

in  railway  carriages,  402 

leaving  retorts,  253 

liquor,  testing  for  CO-2,  374 

free  ammonia,  374 

lost  from  clay  retorts,  244 

made  from  cork  refuse,  253 

by  Din sm ore  process,  253 

from  peat,  resin,  sawdust,  253 

mains,  depth  of,  279 

making  process,  Browne's,  387 

meter  unions,  320 

oxygen  required  for  combustion,  305 

passed  through  sawdust  and  sulphur. 

267 

small  on  lice,  256 


,  pressures  of,  323 

Stove  notes,  314 

supply  pipes,  315 

suction  producers,  403 

,  supply  required  or  cooking.  31* 

tubing,  weight  of,  297 


INDEX. 


449 


Gas  valve  testing,  292 

washed  in  a  tar  seal,  253 

with  mineral  oil,  325 

works  site,  151 

Referee's  standard  burner  43ti 

notification,  412 

Gaseous  firing,  157 

fuel,  gain  with,  241 

products  from  combustion,  346 

Gases,  diffusion  of,  279 

Gasholder  bell,  to  ascertain  weight,  214 

• ,  care  of,  279 

carriages,  224 

columns,  strength  of,  222 

contraction  of  on  lifting,  226 

Gasholders,  cost  of,  210,  219 

,   curbs  trussed,  210 

,   equilibration  chains  for,  214 

,    general  notes,  210 

guides,  220 

,  spiral,  220 

for  Dowson  gas,  401 

in  gales,  279 

joints,  strength  of,  225 

of  cantilever  type,  223 

,  painting,  212,  279 

,   pressure  of,  214 

•    pumps,  209 

sheets,    rivets   required  for, 


212 


side  sheets,  thickness  of,  212 
single  lift,  210 
strains  on  top  sheets,  210 
— ,  Wyatt's  rules,  225 


tanks,  202 

,  frost  in,  279 

— ,  to  increase  weight  of,  210 

,  trussing,  21 2 

,   weight  of,  214 

—  (diagram),  221 


Gasolene,  302 

evaporated  by  gas,  402 

Gauges,  mercury,  357 

,    pressure,  357 

,    in  decimals  of  1  inch,  89 

Gearing,  rope,  189 
Generator  for  water  gas,  393 

furnaces,  gases  in,  240 

,    gas  compression  of,  401 

gases,  proportions  of  CO  jin,242 

,  heat  produced  in,  158 

setting,  157 

Generators,  fuel  in,  393 

,   temperatures  in,  393 

German  words  for  gas  apparatus,  437 
Girders,  area  of  flanges  to,  132 

bearing  surface  for,  132 
camber  on,  132 
cast  iron,  138 
continuous,  139 
relative  strength  of,  138 
thickness  of  web  plates  for,  139 
wrought  iron,  notes  on,  139 


Glass  sheet,  thickness  of  and  weight  of, 

77 
tube,  to  bend,  324 

G.B. 


Globes,  absorption  of  light  by,  309 
Glossary  of  terms,  437 
Glycerine  for  meters,  321 
Governor  bell  area,  321 

cones,  321 

Grabs,  saving  by,  152 
Graduating  photometer  bars,  359 
Grains     sulphur    from     grains    BaSO* 

(diagram),  383 
Granite,  analysis  of,  76 

piers,  safe  load  on,  75 

Grammes,  &c.,  to  convert,  58 
Grates,  heat  evolved  by,  310 
Gravel,  safe  load  on,  75 
Grips  and  cups,  224 
Ground  area  required,  151 
,   bearing  power  of,  202 

under  mains,  291 

Grouting  in  steel  tanks,  203 
Guide  framing  notes,  220 

rollers,  224 


Gun  cotton,  heat  of  explosion,  329 
Gussets  to  gasholders,  210 
Gutters,  fall  in,  80 
Gyration,  least  radius  of,  141 

HALF-round  iron,  weight  of,  130 
Handholes  in  hydraulic  mains,  159 
Harcourt  colour  test,  376 
Harcourt's  pentane  unit,  369 
Hard  coke,  to  obtain,  244 
Hardening  tools,  colours  of,  100 
Hartley  on  testing  station  meters,  319 
Haunching,  229 
Head  of  water,  300 
Heat  absorbed  by  air,  243 

at  exit  of  chimney,  181,  261 

conducting  power  of  solids,  338 

,  effects  of,  247 

equivalent,  166 

evolved  by  gas  flame,  308 

open  grates,  316 


,  expansion,  by,  330 

from  1  Ib.  of  different  substances, 

335 

in  Peebles  retorts,  402 

lost  by  unit  of  surface,  339 

when  charging,  244 


of  combustion  of  fuels,  259 

,  to  find,  347 


retorts,  to  examine,  234 
secondary  air,  241 


produced  in  generator,  158 

— ,  radiant,  89 

required  to  gasify  tar,  402 

of  different  fires,  317 

,  specific,  88 

transmission  of,  176 

units,  166 

evolved  by  substances,  341 

from  carbon,  244,  397 

gas,  340 

hydrogen,  398 


generated  by  lights,  307 
lost  in  gas  engines,  193 

GO 


450 


INDEX. 


Heating  and  lighting  by  same  gas,  356 

coal,  to  indicate,  232 

duty  of  gas,  effective,  341 

feed  water,  261 

gases,  analysis  of,  395 

gas  for  combustion,  308 

power  of  fuols,  260 

; surface  for  boilers,  178 

- value  of  carburetted  water  gas, 


Dowson  gas,  401 


Heats,  best  for  cooking,  317 
Height  of  lamps,  309 

= lifts,  210 

purifiers,  201 

Hefner-Alteneck's  burner,  370 
Hemp  ropes,  strength  of,  109 
Heptane,  302,  353 
Hexagon,  length  of  side  of,  41 
High-pressure  pipes,  thickness  of,  289 

gas  delivery,  285 

temperatures,  carbonising  at,  233 

Hill's  process,  265 

Hod,  bricklayer's,  measurement,  73 

Holes,  drilling  in  mains,  221 

,  leakage  through,  292 

Hoop  iron  in  tank  walls,  205 

,    weight  of,  127 

Hoops  to  tanks,  205 
Horse-power  of  boilers,  174 

Dowson  gas,  400 


falling  water,  87 

gas  engines,  191 

rope  gearing,  189 


required  to  pass  gas,  10G 
to  raise  water,  186 

_ -with  town  gas,  301 

Horse-powers,  to  calculate,  166 

Horses,  power  of,  63 

Hot  lime  sulphided,  274 

Hourly  make  of  gas,  237 

quality  of  gas,  238 

specific  gravity,  237 

Housing  exhauster  plant,  166 
Hundredweight,  decimals  of,  40 
Hydraulic  cranes,  151 

mains,  159 

levelling,  159 

main  liquor  analysis,  253 

overflows,  159 

tar,  253 

—    supports,  159 

,  temperature  in,  254 

valves,  161 

,  water  in,  253 

water  seals  in,  160 


power,  151 

distributing,  151 


rams,  loss  in,  88 

pipes,  loss  of  head  in,  151 

cylinders,  thickness  of,  151 


Hydrochloric  acid,  normal,  345 
Hydrogen,  diluting  effect  of,  255 

escaping  unconsumed,  307 

,  heat  units  from,  """ 


lifting  power  of,  318 
H2S,  action  of  oxide  upon,  269 
— ^,  test  for,  375 
TGNITING  point  of  coals,  2*2 
JL    Ignition  of  gas  engines,  190 
Illuminating  agents,  relative  values  of, 

art?; 

power  by  calorific  values, 
-from  equal  areas  of 


flames,  363 


-  lost  by  air,  244 

,  table  giving,  426 

value  of  acetylene,  353 

ethane,  353 

ethylene,  353 

methane,  353 


values  of  hydrocarbons,  355 
Impurities  in  condensed  gas,  257 
crude  gas,  235 
gas  after  scrubbers,  266 


Incandescent  burners  with  gas  and   air, 
347 

electric  lamps,  313 


Inch,  decimals  of,  47 
I.H.P.,  to  calculate,  169 
Indicating  heating  of  coals,  232 
Indicators,  to  prepare,  843 
Inertia,  moments  of,  136,  144 
.  Inhalation  of  adults,  808 
|  Injecting  air  into  purifiers.  275 

oil  in  water  gas  plant,  393 


Hydrocarbons,  amount  for  enriching,  389 
,— ,  temperature    of  produc- 
tion, 233 

,  to  absorb,  326 

.,  illuminating  value  of,  355 


Inlet  pipes  to  holders,  224 
Inner  lift,  stability  of,  224 

,  stays,  211 

Inorganic  matter  in  coke,  248 
Internal  pipe  fittings,  size  of»809 
Inverted  arches,  66 
Iron  angles,  weight  of,  91,  etc. 

tees,  weight  of,  91,  etc. 

bands  in  concrete  tanks,  207 

bars  in  concrete,  209 

;  burners  and  acetylene,  391 

chains,  strength  of,  109 

,  contraction  of,  by  compression,  213 

,  expansion  of,  213 

,  flat  rolled,  weight  of,  91 

,  half-round,  weight  of,  180 

hoop,  weight  of,  127 

joists,  82 

pipes,  weight  of,  114 

retorts  for  tar  carbonisation,  251 

.round,  weight  of,  131 

,  square,  weightlof,  131 

sheet,  weight.of,  124 

tanks,  202,  203 

testing,  112 

tubes,  safe  pressure  on,  174 

JET  photometer,  261,  857 
Joining  aluminium,  229 

platinum,  229 


INDEX. 


Jointing  for  ascension  pipes,  160 
mouthpieces,  154 


petroleum  pipes,  397 
pipes  with  lead,  292 


Joints  in  dip  pipes,  160 

gasholders,  strength  of,  225 

stonework,  76 

of  millboard,  292 

pipes,  depth  of  yarn  in,  292 


weight  of  lead  in,  288 


• ,  testing  with  soap,  292 

Joists,  iron,  82 

rolled  iron,  diagram  of,  134 

timber,  82,  137 

,  safe  load  on,  86 

Joule's  law,  166,  340 

equivalent  of  heat,  166 

Journals,  engine,  186 

and  space  between,  183 


KEEPING  right  tenrperature  in  puri- 
fiers, 201 

Keys,  proportion  of,  187 
Kindling  explosive  mixtures,  329 


T  ABOUR  required  for  furnaces,  245 

J.J to  carbonise,  244 

Laming  material,  274 
Lamps,  height  of,  309 
Lancashire  boilers,  173 

,  proportions  of,  170 


Latent  heat, 


of  evaporation,  335 

fusion,  338 
liquefaction,  338 


Laths,  angle  iron,  142 

,  for  slating,  distance  apart,  79 

Latticed  standards,  resistance  of,  223 
Layers  of  material  in  purifiers,  198 
Laying  lead,  80 

mains,  291 

permanent  way,  148 

slates,  78 

Lead  jointing,  292 
• laying,  80 

i nails,  96 

pipes  for  services,  292 

pipe,  weight  of,  123 

sheet,  covering  power  of,  90 

,  thickness  of,  80 

,  usual  thickness  of,  80 

,  weight  of,  80 

test  papers  to  prepare,  342 

,  to  unite,  100 

,  weight  of  in  pipe  joints,  288 

,  white,  to  test,  77 

Leakage  in  district,  300 

through  holes  in  plates,  292 

Leak,  finding  in  mains,  292 
Leaks,  in  connections,  to  find,  194 

tanks,  205 

Least  radius  of  gyration,  141 
Length,  measures  of,  43 
of  flame,  356,  399 


Length  of  side  of  decagon,  41 

dodecagon,  41 

hexagon,  41 

octagon,  41 

Levelling  hydraulic  mains,  150 

Liability  of  water  to  freeze  in  tanks,  203 

Lifting  power  of  gases,  318 

purifiers,  201 

Lifts,  depth  of,  212 

Light  absorbed  by  globes,  309 
areas  covered  by,  358 
carbon  di-oxide  produced  by,  305 
comparative  cost  of,  313 
decomposition  by,  360 
from  standard  burner,  369 
heat  units  generated  by,  307 
lost  by  addition  of  air,  347 
mechanical  equivalent  of,  356 
minimum  required,  307 
theory  of,  354 
velocity  of,  356 

Lighting  and  heating  by  same  gas,  356 

power  of  acetylene,  391 

table,  309 

up  water  gas  plant,  393 

Lightning  conductors,  181 

for  chimneys,  159 


Lime,  absorptive  power  of,  278,  372 

,  action  on  CO2  and  H-2S,  272 

,   caking  in  purifiers,  270 

,   combining  with  water,  271 

,  earthy  matters  in,  270 

,   increase  of  bulk  when  slaked,  271 

,   made  from  chalk,  270 

,   quantity  required  to  purify,  270 

required  for  C02,  270 

sheds,  198 

.    slaking  before  use,  271 

testing,  372 

,  thickness  on  grids,  271 

,   water  for  testing,  342 

in,  271 

,   weight  of,  270 

,  wet,  for  purifying,  271 

Limestone,  value  of,  270 
Limiting  explosive  mixtures,  329 
Limit  of  heat  in  settings,  240 

weights  of  wrought  iron,  140 

Linear  expansion,  coefficients  of,  89 
Line,  to  divide,  64 
Lining  water  gas  vessels,  393 
Linseed  oil,  boiled,  77 
raw,  77 


Liquefaction,  latent  heats  of,  338 
Liquid  air,  density  of,  328 

fuel,  242 

measure,  44 

measures,  equivalent,  56 

[.i-iuids,  expansion  of,  332 

by  heat,  338 


quor,  amount  of  sulphate  from,  404 
— ,  analysis  of,  264 

-    freed  from  CO2,  263 
—   from  condensers,  contents  of,  256 

in  hydraulic  mains,  253 

scrubbers,  196 

GO  2 


462 


INDEX. 


Liquor  made  from  coal,  165 

,  ounce  strength  of,  375 

= ,  standard  test  solution  for,  343 

tanks,  165 

— ,  testing  for  CO-2,  374 

free  ammonia,  374 

Lithium  hydride,  353 
Litmus  papers,  342 

to  prepare,  343 

Load  on  roofs,  78 
,  safe,  on  piers,  75 

rolled  iron  joists,  134 

Loads,  dead,  in  buildings,  87 
,  live,  on  buildings,  87 

on  floors,  82 

Loam  earth,  resistance  of,  204 
Locomotives,  heated  by  petroleum,  24- 

,  tractive  force  of,  14s 

Logarithms,  1 

described,  23 

London  gas,  analysis  of,  349 
Long  measure,  43 

pipe  condensers,  167 

Loss  by  storage,  279 

of  ammonia,  to  prevent,  265 

-  head  in  hydraulic  pipes,  151 

heat  in  condensers,  164 

when  charging,  244 


gas  in  purifiers,  267 


light  through  gas  travelling,  30] 

weight  by  stacking  coal,  231 

Losses  in  boilers,  engines,  and  electrici 
plants,  169 

direct  fired  settings,  239 


Lowe  oil  gas,  analysis  of,  592 
Lubrication  for  exhausters,  258 
Luminosity,  cause  of,  in  gas  flame,  355 
Luminous  effect  of  flame  areas,  314 
Lutes  in  purifiers,  198 

,    steam  in,  224 

Luting  materials,  244 

MACHINE  belting,  187 
stoking,  space  for,  153 

Mahler's  calorimeter,  249 
Mainlaying,  291 
Mains,  281 

,  coating  for,  291 

,  covered  with  felt,  291 

,  depths  for,  279 

,  dimensions  of,  286 

,  drilling  holes  in,  291 

,  fall  required  in,  291 

in  works,  of  wrought  iron,  165 

,  small  services  from,  291 

— ,  temperatures  in,  300 
— ,  testing  in  district,  291 
— ,  with  sleepers  under,  291 

Maintaining  flame  at  constant  height,  307 

Maintenance  of  metal  tank,  203 

Make  of  gas  per  hour,  237 

liquor,  165 

Making  oxygen,  276 

roads,  146 

sulphuric  acid,  405 

Manilla  ropes,  strength  of,  189 


Man  power,  63 

Man's  strength,  228 

Manure,  sulphate  as,  406 

Marks  on  photometer  bars,  359 

Mariotte's  law,  365 

Marsh  gas,  description  of,  352 

,  particulars  of,  325 

Materials  for  luting,  244 

roof,  weight  of,  78 

required  for  railway,  148 

settings,  15(J 


weight  of,  60 


Mathematical  tables,  1 
Maximum  wind  pressure,  216 
Measurement  of  coals,  145 
coke,  145 


Measures  and  weights,  42 

of  capacity,  44 

length,  43 

Measuring  pipes,  293 

Mechanical  efficiency  of  gas  engines,  T9I 
—  steam  engines>  166 

equivalent  of  light,  356. 

Melting  iron,  cupolas  for,  14A 

points,  247,  330 

—   of  alloys,  250,.  335 

elements.  322 

metals,  98;  33£ 

solids,  334 

Memoranda,  electrical,  350. 
Mending  broken  pipe,  292 

Men  employed  in  carbonising,  245 

required  for  water  gas  plant,  393 

Mercury,  comparison  of,  S& 

gauges,  257 

,  pressure  of,  299 

,  weight  of,  357 

Metals,  comparative  strength  of,  130 
weights.  128 


,  coefficient  of  expansion  of,  334 

,  effect  of  heat  on,  114 

,  electrical  conductivity  of,  98 

— — ,  melting  points  of,  334 

,  safe  stresses  on,  128 

,  specific  heats  of,  334 

— ,  weight  of  square  foot  of,  128 
Methane,  description  of,  852 

,  illuminating  value  of,  353 

Meters  at  high  and  low  pressures,  321 

,  dry  average  tests  of,  321 

,  effect  of,  on  illuminating  powe: 

of  gas,  321 

,  fixing,  321 

,  glycerine  for,  321 

,  for  gas  engines,  192 

,  station,  229 

,  to  prevent  freezing,  321 

,  wet,  particulars  of,  319 

,  unions  for,  320 


Methyl  orange,  to  prepare,  343 
Metric  equivalents,  56 

liquid  measure,  56 

measures  of  length,  56 

Metropolitan  Argand  burner  No.  2,  425- 
Metropolitan  Building  Act,  72 
Mile,  decimals  of,  47 


INDEX. 


453 


Millboard  joints,  292 
Minimum  light  required,  307 
Mixing  concrete,  73,  209 

gases,  279,  234 

—  puddle,  204 

•  water  at  different  heats,  339 

Mixture  for  stucco,  73 
Mixtures,  freezing,  337 
Moist  air  in  photometer  rooms,  358 
Moisture  in  air,  31  i 

coal,  251 

coke,  244 

Moments  of  inertia,  136,  144 

Money,  to  convert  to  decimals  of  £1,  45 
Monier  system,  74 
Mortar,  72 

,   best  sand  for,  73 

,  in  frost,  74 

,   strength  of,  72 

,  water  required,  73 

Morticing,  229 

Motive  power  from  acetylene,  390 

gases,  194 

Motor,  cost  per  horse-power,  318 
Mouthpieces,  jointing  for,  154 

,  size  of,  155 

,  weight  of,  160 

,  yield  per,  157 

Multipost  gasholder  framing,  222 


N 


AILS,  copper,  weight  of,  98 

for  slating,  zinc,  79 

,    lead,  slating,  96 

• ,    slate  galvanised,  96 

Names  of  gas  apparatus  in  French  and 

German,  437 
Napthalene,  310 

and  cannel,  386 

as  an  enricher,  302 

compared  with  benzene,  387 

,    description  of,  352 

,    fixing  point  of,  256 

in  condensers,  164 

gasholder  pipes,  279 

scrubbers,  262 

tar,  409 

works,  256 

— ,    preventing     deposition     in 
works,  256 

,    tests  for,  256 

,    to  clear  from  condensers,  256 

with  dry  gas,  256 

Natural  gas,  composition  of,  351 

slopes  of  earths,  202 

Newcastle  coal,  ash  from,  251 

Nitrate  of  soda  compared  with  sulphate, 

405 
Nitrogen,  combination  in  coal,  384 

in  coals,  265 

for  sulphate,  404 

reduces  light,  347 

Noises  in  exhaust  pipes  of  gas  engines. 

192 

Nominal  horse-power,  166 
Non-conducting  materials,  182 


Non-conductors  for  steam  pipes,  184 
Normal  hydrochloric  acid,  345 

oxalic  acid,  345 

sodium  carbonate,  345 

hydrate,  345 


solutions,  equivalent,  346 

sulphuric  acid,  345 

Notes,  electrical,  350 
on  boilers,  173 

chains,  111 

coai  stores,  148 

gas  stoves,  314 

—  guide  framing,  220 

•  Pole's  formula,  294 

pumps,  284 

riveting,  108 

ropes,  111 

ventilation,  311 

wrought-iron  girders,  132 


Notification  ol  Gas  Referees,  412 
Numbei  of  burners  required,  311 

feet  for  Id.  (diagram),  303 

Numbers,  to  square,  41 
Nuts,  proportions  of,  102 
,  weight  of,  102 

OBLIQUE  illumination,  307 
Octagon,  length  of  side  of,  41 
Oil  engines,  194 

—  for  exhausters,  258 

—  gas  tar,  analysis  of,  396 
•   as  paint,  277 

• ,  water  in,  397 

—  linseed  boiled  and  raWj  77 
— ,  sperm,  light  from,  402 
Oils,  storing,  232 

Old  candles,  361 

Olefiant  gas,  description  of,  352 

Olefine  series,  particulars  of,  325 

Ordinary  joints,  weight  of  lead  in,  285 

Oscillation  in  retorts,  247 

Otto  cycle  gas  engines,  190 

Ounce  strength  of  liquor,  375 

Outlet  pipes  to  holders,  224 

Oval,  area  of,  41 

Overflow  to  hydraulic  main,  159 

Overheating  boilers,  175 

Overturning  of  wind  and  snow,  223 

Oxalic  acid,  normal,  345 

Oxidation  of  sulphur  compounds,  274 

Oxide,  analysis  of,  267 

,    back  pressure  from,  268 

,    combining  power  of,  268 

,    compared  with  Weldon  mud,  274 

,    expansion  of,  268 

,    heating  when  new,  269 

in  paint,  280 

,    new,  268 

of  iron,  effect  on  CSg,  267 

—  paint,  71 


purifiers,  reaction  in,  268 

,    purifying  power  of,  268,  373 

surface  required,  272 


,    revivifying,  373 

sheds,  198 


454 


INDEX. 


Oxide,  spent,  analysis  of,  269 

for  cyanides,  269 

testing,  373 

,    thickness  of  layers,  268 

,    to  revivify,  268 

,    value  of,  when  spent,  269 

,     weight  of,  268 

Oxidising  gasholder  sheets,  211 
Oxygen  added  to  gas,  385 

and  ethylene  mixed,  387 

consumed  by  lights,  305 

,  detecting  in  coal  gas,  378 

purification,  275 

: —    required  by  acetylene,  benzene, 

ethylene,  marsh  gas,  355 

for  combustion  of  fuel, 


259 


305,  32f 


purification,  276 
support  combustion, 


•  flames, 


to  prepare,  27( 


PAINT,  covering  power  of,  76 
Painting  gasholders,  212,  279 

gas  stoves,  314 

purifier  covers,  277 

Paint,  oxide  of  iron,  77 

Paper,  drawing,  sizes  of,  59 
Paraffin  series,  particulars  of,  325 
Paris,  plaster  of,  74 
Particulars  of  dry  meters,  320 

wet  meters,  319 

Pavements,  tar  for,  317 
Paving,  York,  weight  of,  76 

slabs,  74 

Peat,  gas  made  from,  253 
Pedestal  proportions,  186 
Peebles  oil  gas  as  an  enricher,  402 

process,  402 

,  coke  from,  402 

,  gas  from  tar  by,  402 

Pens  for  registering  pressure  gauges,  319 
Pentane,  371,  423 

unit,  Harcourt's,  369 

,    ten  candle,  420 

Percentage  of  coal  in  its  use,  250 
Permanent  way  work,  148 
Peroxide  of  iron,  373 
Perpendicular,  to  set  out,  64 
Petroleum,  analysis  of,  386 

,  as  fuel,  176 

•  furnaces,  244 

heated  locomotives,  244 

lamp,  light  from,  307 

pipes,  to  joint,  397 

tank,  to  protect,  397 

. vapour  explosions,  385 

Phenanthrene,  353 
Photometer  bar,  divisions  of,  358 
graduating,  359 


discs,  359 

with  three  spots,  359 

jet,  357 

rooms,  moist  Uir  in,  358 


Photometer  rooms,  ventilation,  358 

,  shadow,  358 

table,  the,  422 


Photometers  with  sliding  candles,  360 
Piers,  safe  load  on,  75 
Piles,  64 

,   safe  load  on,  75 

Pillars  of  brick  and  stone,  69 

pine,  breaking  load  on.  84 


Pine  beams,  safe  load  on,  85 

pillars,  breaking  load  on,  84 

,  safe  load  on,  75 

Pintsch  system,  402 
Pipe,  broken,  to  mend,  292 

condensers,  163 

,  composite,  weight  of,  123 

fittings,  internal,  size  of,  309 

flanges,  proportions  of,  122 

joints,  depth  of  yarn  in,  292 


-,  temporary,  292 


-  ,  repairing  cement,  292 

-  ,  casting,  288 

-  ,  coatings  for,  123,  291 
Pipes,  contents  of,  90 

—  ,     copper,  weight  of,  124 

-  damaged  by  electricity,  291 

-  ,    depth  underground,  291 

—  dimensions  of,  286 
distributing  power  of  (diagram^ 


282 


drilling  holes  in,  291 
effects  *of  rough  insides,  291 
fall  required  in,  291 
for  gas  stoves,  315 
—    steam  heating,  316 
in  bad  soils,  291 
lead,  weight  of,  123 
measuring,  296 

outside  covered  with  felt,  291 
service,  coating,  292 
testing,  288 
weight  of,  114 

,  (diagram),  120 


with  sleepers  under,  291 

Pistons,  effective  pressures  on,  169 
Pitch  for  briquettes,  317 

pine  beams,  safe  load  on,  85 


Placing  concrete,  209 

puddle,  204 

Planing  purifier  plates,  200 
Planks,  82 

Plant  for  semi-water  gas,  401 
Plaster  of  Paris,  74 
Plates,  allowance  for  lap  of,  213 
,  flat,  strength  of,  143 

in  tanks,  203 

transverse  strength  of,  140 


Platinum,  jointing,  229 
Pointing,  72 

and  facing,,  74 

,  flat  and  tuck,  74 


Pole's  formula,  notes  on,  294 
Poor  gas  deposits  iiapthalene,  256 
Porosity  of  stone,  76 
Portland  cement,  use  of,  73 
stone,  analysis  of,  70 


INDEX. 


455 


Portland  stone  piers,  safe  load  on,  75 
Position  for  enriching  apparatus,  402 
Potassium  hydroxide,  344 
Pound  sterling,  decimals  of,  45 

weight,  decimals  of,  48 

Pounds  water  heated  by  gases,  331 
various    sub- 
stances, 331 

Power  from  calcium  carbide,  176 
,    hydraulic,  151 

of  daylight,  307 

horses,  63 

men,  63 

oxide  to  remove  sulphur,  269 

puddle  to  retain  water,  204 

reflecting  heat,  89 

the  eye,  358 

water  fall,  88 

to  dissolve  benzene,  &c., 

388 

required  to  raise  water,  184 

,    results  of,  63 

Preparing  oxygen,  276 
Preservation  of  belting,  187 

scaffold  cords,  72 

timber,  81 

Pressure  from  calcic  carbide,  301 
washers,  190 


—  in  gas  engines,  190,  401 
puddle  tanks,  205 

— •  retorts,  247 
-   water  gas  shells,  393 

—  gauges,  357 

pens  for,  319 


of  air  blast  in  water  gas,  393 

-  column  of  water,  324 

-  gasholders,  214 

(diagram),  221 

-  mercury,  299 

-  snow  on  gasholders,  214 

-  water.  299 


plane,  206 


against      a      vertical 

at  different  levels,  207 
on  tank  sides,  206 


217 


vapour,  327 

wind, 216 
at    different   heights, 


on  circular  objects,  218 
in  different  places,  216 
on  different  areas,  217 
spheres,  219 


boiler  furnace  tubes,  174 
district,  300 
flames,  356 
foundations,  65 
guide  columns,  218 
retorts,  effect  of,  244 
tank  walls,  203 
safe  on  boilers,  174 


Pressures  thrown  by  lime  purifiers,  271 
Preventing  boiler  incrustations,  261 

deposition  of  napthalene    in 

works,  256 
— • meters  freezing,  321 


Preventing  oscillation  in  retorts,  165 

priming,  261 

stopped  pipes,  246 

Primary  air  in  furnaces,  240 
Priming,  to  prevent,  261 
Producer  and  water  gas  mixed,  398 

gas  and  flame  temperature,  385 

,  Siemens,  400 


gases,  composition  of,  241 
•suction,  403 


Producers,  steam  required  for,  243 
Production  of  aniline,  409 
Products  of  coal,  255 

combustion,  356 

from  burners,  308 


crude  oil,  381 
distillation,  381 

-of  coal,  235 


tar,  381 

works,  chimneys,  404 

Propane,  353 

Proper  height  of  lamps,  309 
Properties  of  circles,  41 
Proportions  of  belts,  188 

— boilers,  170 

bolts  and  nuts,  102 

—    CO-2  in  generator  gases,  242 

chimneys,  177 

—    crane  hooks,  150 

•    enriching  gas,  to  find,  385 

keys,  187 

• pedestals,  186 

pipe  flanges,  122 

riveted  joints,  104,  175 

rivets,  107 

tar  concrete,  317 

teeth  of  wheels,  187 

tie-rods,  142 

treads  and  risers  to  stair- 


washers,  102 


Protection  areas  of  lightning  conductors, 

181 
Prussian  blue,  196,  276 

in  cyanogen  liquor,  384 


Puddle  tanks,  pressures  in,  205 

,  mixing,  204 

,  placing,  204 

,  weight  of,  204 

Pulleys  for  rope  driving,  188 

,  rims,  width  of,  187 

Pump  notes,  184 
Pumps,  166 

,    capacities  of,  185 

for  gasholders,  209 


Punches,  228 

Pure  air,  contents  of,  311 

Purification  by  ammonia,  201,  263 

Glaus  process,  201 

ith  oxygen,  275 


Purified  gas,  composition  of,  277 

Lowe  oil  gas,  analysis  of,  392 

Purifier  connections,  198 

covers,  201 

fastenings,  200 

lutes,  19* 


456 


INDEX. 


Purifier  seals,  148 
Purifiers,  197 
,  area  of,  197 

for  sulphur  purification,  197 

,  height  of,  201 

in  sulphate  plant,  404 

,  lifting,  201 

,  loss  of  gas  in,  267 

Purifying,  267 

power  of  oxide,  268,  373 

sheds,  197 

value  of  lime,  372 

water  gas,  396 

Purlins,  angle  iron,  142 
Purity  of  benzol,  388 
Putlogs  in  scaffolding,  72 

Putty  for  temporary  pipe  joints,  292 
Pyrogallic  acid,  to  prepare,  345 
Pyrometers,  249 


/DUALITY  of  bricks,  67 
\^  --    gas  per  hour,  238 
Quantity  of  acetylene  from  carbide,  391 
•  --    cyanogen  obtainable,  276 
--    lime     for     purifying     with 

oxygen,  276 
--    riveting  in  gasholders,  211 

sulphur  absorbed  by  oxide, 


269 


compounds       from 


coal,  273 


T)  ACK  and  pinion  valves,  dimensions  of, 

Radial' rollers,  effect  of,  211 
Radiant  heat,  89 
Radiating  power  of  solids,  339 
Radius,  least  gyration  of,  141 

of  crowns,  225 

protection  of   lightning  con- 
ductors, 181 
Rails,  149 

,    strength  of,  131 

Railway  carriages,  gas  in,  402 

,    materials  required  for,  148 

Rainfall,  maximum,  79 

per  hour,  79 

Raising  temperature  of  purifiers,  275 

water,  power  required  for,  185 

Rags  soaked  with  oil,  326 

Rams,  hydraulic,  88 

Rate  of  station  meters,  229 

travel  through  purifiers,  197 

Raw  linseed  oil,  77 

Reaction  in  oxide  purifiers,  268 
of  cyanides,  196 

liquor  and  sulphuric  acid,  404 

oxide  when  revivifying,  269 

Reciprocals,  1 

Recovering  cyanogen,  265 
Red  litmus  paper,  to  make,  342 

• lead,  setting  of,  280 

Reduction  of  temperature  of  waste  gases, 


Reduction  of  illuminating  power  by  CO2, 
267 

pressures  in  pipes,  281 

Referees,  notification  of,  412 
Reflecting  power  of  ceiling,  307 
—  solids,  339 


radiant  heat, 


Reflection  of  different  substances,  311 
Refrigerating  coal  gas,  401 
Regenerative  settings,  157 
Regulations  for  testing,  410 
Relative  carrying  capacities  of  pipes,  285 

strength  of  beams,  138 

girders,  138 


values  of  illuminating   agents, 


305 
Removal  of  ammonia,  196 

C02,  271 

€82  by  scrubbers,  263 

•    cyanogen  compounds,  277 

•    sulphur  compounds,  272 

tar,  255 


Removing  dip  pipe  seals,  160 
tar,  164 


Rendering  tank  walls,  209 
Repair  of  furnaces,  243 
Repose,  angle  of,  62 
Residuals  from  crude  gas,  235 
Resin,  gas  made  from,  253 
Resistance  of  beams,  136 

cohesion  of  wall,  203 

curves,  149 

damp  sand,  204 

earth  backing,  203 

lattice  standards,  223 

loam  earth,  204 

round    cast-iron  columns, 


-  trains,  149 

-  web  plate  standards,  223 

-  weight  of  tank  walls,  203 
to  crushing,  68 

stones,  75 


223 


loads,  safe,  75 

shearing,  106 

torsion,  107 

traction  OH  roads,  147 


Results  of  distilling  tar,  407 

power,  63 

Retort,  clay,  life  of,  243 

house,  area  required,  154 

chimney,  158 

•,  constructing,  151 

drains,  154 

,  floor  joists  for,  154 

,  roof  trusses  for,  154 


houses,  compressed  air  in,  154 

,  ventilation  of,  154 

-,  width  of,  154 


Retorts,  153 

,  carbon  in,  247 

,  circular,  155 

,  clay,  155 

,  effect  of  pressure  in,  244 

,  for  Peebles  process,  402 

• ,  heat  of,  to  examine  234 


INDEX, 


457 


Retorts,  iron  for  tar  carbonisation,  251 
— ,  oscillation  in,  247 

,  space  above  coal,  233 

around,  154 

,  temperature  in,  254 

•,  through,  155 

,  velocity  of  gases  in,  234 

,  yield  per  square  foot,  234 

Reversing  photometer  discs,  359 
Revivification  of  oxide  in  air,  273 
Revivifying  oxide,  373 

,  reaction,  269 

Right  angles  to  set  out,  64 

Rising  pipes,  curves  in,  160 

Riveted  joints,  proportion  of,  104,  175 

to  plates,  strength  of,  107 

Riveting  crown  sheets  to  trussing,  211 

gasholders,  212 

notes,  108 

,  quantity  of,  in  gasholders,  211 

thick  to  thin  plates,  213 

Rivets,  allowance  for  waste  on,  213 

heads,  weight  of,  106 

,  proportions  of,  107 

required  for  gasholder  sheets,  212 

,  shearing  resistance  of,  108 

— — • strain  on,  226 

,  size  of,  for  boiler  plates,  175 

plates,  106 


strength  of,  105 


Road  making,  146 

tramways,  147 

Roads,  gradients  in,  147 
Rocks,  weight  of,  62 
Rod- of  brickwork,  69 
Rods,  round,  strength  of,  130 
Rolled  joists,  diagram,  134 

iron,  weight  of,  91 

T-iron,  strength  of,  142 

Rollers  radial  and  tangential,  effect  of,  211 

Roman  cement,  74 

Roof,  area,  to  calculate,  78 

coverings,  79 

Roofing,  All  port's  waterproof,  80 

,  Willesden,  80 

Roof  materials,  weight  of,  78 

sheeting,  corrugated,  98 

trusses,  height  of,  in  retort  house, 

154 
Roofs,  allowance  for  snow  on,  79 

,  curved,  80 

,  load  on,  78 

— ,  wind  allowance  on,  79 

Room  heating,  316 

temperature,  308 

Rope  driving  pulleys,  188 

gearing,  189 

Ropes,  notes  on,  111 

,  safe  working  loads  on,  112 

,  strains  round  pulleys,  112 

,  strength  of,  109 

,  wire,  on  pulleys,  232 

Round  rods,  strength  of,  130 

station  meter,  dimensions,  230 

Rule  for  correcting  for  rate  of  burning  of 

gas,  363 


Rule  for  height  of  lamps,  309 

position  of  hoops  to  tanks,  20.r> 

thickness  of  tanks,  205 

weight  of  pipes,  115 

,  to  find  intensity  of  light,  310 

Rumford  photometer,  358 

Rusting  of  wrought  iron  framing,  220 

Rust  joint  cement,  127 


S 


AFE  load  on  floors,  78 

piers,  75 

rolled  iron  joists,  134 


timber  joists,  86 

pressure  on  boilers,  174 

resistance  to  loads,  75 

stresses  on  metals,  128 

Safety,  factors  of,  89 

on  stones,  76 


tubes  in  blast  mains,  393 

valves,  176 

Safe  working  loads  on  ropes,  112 

Salts  in  tar,  235 

Sand  and  cement,  strength  of,  72 

,  best  for  mortar,  73 

,  value  of  in  mortar,  72 

,  in  mortar,  size  of,  73 

,  resistance  of,  204 

Saturated  hydrocarbons,  325 
Saturator,  temperature  in,  405 
Saving  by  conveyor,  152 

grabs,  152 

steam  jacketing,  168 


Sawdust,  gas  made  from,  253 
Saws,  best  rate  for,  228 
Scaffold  cords,  to  preserve,  72 
Scaffolding,  72 
Scavenging  gas  engines,  193 
Schneider's  heat  testing  cones,  249 
Screw  threads,  125 
Scrubbers,  ammonia  removed  by,  262 
— ,  ammonia  at  outlet,  2(56 
—  and  washers,  195 


,  boards  for,  195 

.effects  of  temperature  upon, 


filled  with  coke,  195 
for  water  gas,  393 
.napthalene  in,  262 
,  surfaces  in,  195 
,  water  required  in,  262 
-,  wetting  material  in,  26? 


Scrubbing  and  washing,  262 
Seals  of  purifiers,  198 
Seams  in  furnace  flues,  170 
Seasoning  timber,  81 

time  required  for,  83 


Secondary  air,  distribution,  157 

,    heat  of,  241 

in  furnaces,  240 

warming,  158 


Seger's  cones,  249 
Segment,  area  of,  41 
Semi-water  gas,  401 
Separating  tar  by  friction,  159 
Service  pipes,  coating,  292  296 


458 


INDEX. 


Services,  connecting,  296 

from  small  mains,  291 

of  lead  pipe,  292 

to  photometers,  363 

Setting  out  curves,  147 

right  angles,  64 

Bettings  cost  of,  156 

covering  for,  154 

direct  fired,  losses  in,  239 

for  boilers,  176 

generator,  157 

limit  of  heat  in,  240 
materials  required  for,  156 
steam  under  bars,  243 
temperatures  in,  241 
.  walls  of,  154 

Sewerage,  66 

Shadow  photometers,  358 

Shafts  for  boilers,  181 

Shale  oil,  distilling,  385 

Sheard's  tests  for  NH3,  CO2,  H2S,  375 

Shearing  resistance  of  rivets,  108 

to,  106 

strain  on  rivets,  226 

Sheet  brass,  weight  of,  124,  130 

glass,  thickness  of,  77 

,  weight  of,  77 

iron,  weight  of,  124 

lead,  covering  power  of,  96 

,   usual  thickness,  80 

weight  of,  80 


zinc,  weight  of,  96 

Sheds  for  purifiers,  197 

Shrinkage  of  castings,  99 

Side  plates,  strains  on,  225 

sheets  of  gasholders,  thickness  of,  21? 

purifier  covers,  201 

Siemens  producer  gas,  400 
Simple  sulphate  plant,  404 
Single  lift  gasholders,  210 
Six-hour  charges,  238 

Size  and  weight  of  slates,  79 

of  brickwork  materials,  67 

box  tinplates,  97 

—  chimney  for  boilers,  178 

—  connections  in  works,  162 

—  drawing  paper,  59 
flues,  158 

holders  in  works,  210 

internal  pipe  fittings,  309 

•  mouthpieces,  155 

photometer  rooms,  358 

purifiers,  197 

rivets  for  boiler  plates,  175 

plates,  106 

sand  in  mortar,  73 

service  pipes,  293 

stables,  146 

Slabs,  paving,  74 

Slaked  lime,  weight  of,  272 
Slaking  coke,  244 

lime  before  use,  271 

increases  bulk,  271 

,  water  required,  201 

Slate  nails,  galvanised,  96 

• ,  lead,  96 


Slate  nails,  zinc,  70 
Slates,  good,  to  judge,  79 

,  laying,  78 

,  sizes  and  weights,  79 

,  to  test,  79 

,  weights  and  sizes,  79 

Sleepers  under  mains,  291 
Sliding  candle  photometers,  360 
Sloping  retorts,  carbon  in,  247 
Slow  condensation,  164 
Slopes  of  earths,  62,  202 
Smith's  forge,  air  in,  229 
Smooth  surfaces  to  retorts,  155 
Snow,  allowance  for  on  roofs,  79 
,    pressure  of,  on  gasholders,  214 

— ,    weight  of,  214 
Soap  for  testing  joints,  292 
Socket  joints,  dimensions  of,  289 
Sockets,  weight  of,  290 
Sodium  carbonate,  normal,  345 

flames,  357 

hydrate,  normal,  345 


Solar  distillate,  396 
Soldering,  flux  for,  124 
Solids,  melting  points  of,  334 

,  power  of  for  conducting  heat,  338 


Soot  from  coal  fires,  317 
Sound,  speed  of,  88 

in  air,  328 


Space  above  fuel,  155 

around  retorts,  154 

between  bearings  for  shafts,  183 

tire  bars,  155 


for  machine  stoking,  153 

occupied  by  coals,  145 

for  fuel,  260 


Spaces,  volume  of,  in  concrete,  74 
Specific  heat,  88 

.  of  air,  241 

bodies,  336 

fire-clay,  152 

metals,  334 


346 


37H 


-gravity  of  bricks,  69 

compared  with  Twaddel, 


-  of  benzene,  388 

—  caking  coal,  252 

—  carbide,  391 

—  coal  to  obtain,  380 

—  elements,  322 

—  gases  to  obtain,  354, 

—  ten  per  cent,  acid,  375 

—  water  gas,  352 
per  hour,  237 


Speed  of  condensation,  164 

cutting  tools,  228 

sound,  88 

in  air,  328 


,    safe  of  flywheels,  187 

Spent  oxide,  analysis  of,  269 

,    testing,  373 

value  of,  269 


Spermaceti  for  candles,  361 
Sperm  light  of  oil,  402 
,  value  of  gas  in,  380 


INDEX. 


459 


Sphere,  volume  of,  41  !  Stoking  boilers,  260 

}  wind  pressure  on,  219  J  stone,  Bath,  weight  of,  7 

Spiral  gasholder  guides,  220  { pillars,  69 

Spoiling  gas  with  too  much  air  in  purifl-   , porosity  of,  76 


cation,  275 

Spontaneous  combustion,  326 
Square  iron  and  steel,  weight  of,  131 
Square  measure,  43 
of  a  number,  41 

roots,  1 

Squares,  1 

Stability  of  gas  with  benzol,  887 

hydrocarbons,  325 

inner  lifts,  224 

sulphided  lime,  274 

Stabling,  146 
Stacking  coal,  231 

coke,  232 

Staircases,  treads  and  risers,  80 
Standard  burner  of  Gas  Referees,  435 

candles,  360  f 

,  Carcel,  370 

,  Hefner- Alteneck's,  370 

liquor  solution,  343 

Pentane,  ten  candle,  420 

Standards,  bending  moment  of,  223 

,  distortion  of,  223 

,  latticed,  resistance  of,  273 

,  strength  of,  220 

— ,  web  plate,  resistance  of,  223 
Starting  gas  engines,  193 
Station  meters,  capacities  of,  229 

dimensions,  230 

drums,  230 

groaning,  319 

.  rate  of  working,  229 

,  testing,   Hartley's  notes,; 

Steam,  condensation  of,  182  [319  ; 

engine,  calorific  power,  191 

,  mechanical  efficiency,  166J 

,  water  consumption  in,  261 

for  ejecting  tar,  242 

warming,  315 

in  lutes,  224 

purifiers,  275 

jacketing,  saving  by,  168 

pipes,  expansion  in,  182 

for  boiler,  182 

• ,  thickness  of,  182 

•  pressure  for  water  gas,  393 
producer,  243 
in  Dowson  producer,  401 


steps,  81 

work,  joints  in,  76 

.York,  weight  of,  76 

Stones,  resistance  to  crushing. 
Stopped  pipes,  to  prevent,  246 
I  Stopping  gas  engines,  193 
I  Storage  for  coals,  145 
— ,  loss  by,  279 

I of  materials,  145 

|  Stores,  coal,  145,  149 
Storing  materials,  231 
oils,  232 


Stourbridge  fire-clay,  152 

Strains  in  gasholders,  Wyatt's  rules,  225 

ropes,  112 

on  crowns  with  different  rises,  213 

side  plates,  225 

top  sheets  of  gasholders,  210, 

211 
Strength,  breaking,  101 

,  comparative,  of  metals,  130 

,  clastic,  101 

,  transverse  of  plates,  140 

of  a  man,  228 

belting,  188 

boilers,  173 

bolts,  103 

brick  columns,  68 

— cast  iron  pipes  as  girders,  144 

cement  and  sand,  72 

chains,  lOt) 

concrete,  75 


—  cylindrical  beams,  222 
double  headed  rails,  131 

— -  English  bond,  72 

—  flat  plates,  143 

gasholder  columns,  222 

joints,  225 


tubing,  weight  of,  297 
under  bars  of  settings,  243 


Steatite  for  burning  tips,  308 
Steel  angles,  weight  of,  91,  etc. 

curbs  for  gasholders,  211 

cylinders,  strength  of,  171 

effect  of  heat  on,  114 

joists,  breaking  weight  on,  138 

• ,  round  and  square,  weight  of,  131 

tanks,  203 

tees,  weight  of,  91,  etc. 

,  testing,  112 

Stiffeners,  vertical,  211 
Stockn*mming,  205 


guide  framing,  220 
manilla  rope  gearing,  1S9 
mortar,  72 
rivets,  105 

riveted  joints  to  plates,  107 
ropes,  109 
round  rods,  130 
steel  cylinders,  171 
tank  walls,  to  calculate,  201 
T-iron,  142 
timber,  82 

wrought-iron  cylinders,  171 
in  gasholders,  220 


j  Stresses  safe  on  metals,  128 

Strontium  flames,  357 

Struts  in  gasholder  framing,  224 

, of  angle  iron  or  steel,  140 

I T-iron  or  steel,  140 

Stucco,  mixture  for,  73 
I  Suction  gas  prod  ucers,  403 
I pipes  for  pumps,  184 

Sugg's  burners,  369 

Sulphate,  amount  from  liquor,  404 
I as  manure,  406 


460 


INDEX. 


Sulphate  from  coal,  404 

made  in  1894,  405 

plant  condensers,  404 

-,  fuel  required,  405 


-,  purifiers,  404 
-,  simple,  404 


-    of  iron,  373 

-,  time  required  to  manufacture, 


405 
Sulphide  from  hot  lime,  274 

of  lime,  373 

Sulphided  lime,  air  with,  273 

purifiers,  action  in,  273 

,  effect   of    CO2 


upon,  273 


upon,  273 


H.,S 


stability  of,  274 


Sulphocyanic  acid,  277 

Sulphur  compounds  from  water  gas,  396 

,    oxidation  of,  274 

,    quantity  from  coal, 


removal  of,  272 
temperature  of  for- 


Tank  walls,  rendering,  209 

,   resistance  of  weight  of,  203 

,  thickness  at  base,  205 

of,  203 


Tanks,  asphalte  for,  209 

,  brick,  205 

,  details  of,  209 

,  hoops  to,  205 

for  gasholders,  202 

,  foundations  for,  202 

,  leaks  in,  205 

• —  for  liquor  and  tar,  165 

,  sides,  pressures  of  water  on,  206 

,  rules  for  thickness  of  cylinder,  20i> 

,  to  calculate  strength  of  walls,  207 

•,  wrought  iron,  thickness  of  (dia- 


lation,  244 

from  damp  coal,  233 

gas  burning,  308 


gram),  208 
Tar,   analysis  of,  407 
,  oil  gas,  analysis  of,  396 

and  liquor  tanks,  area  of,  165 

as  fuel,  244 

,  average  yield  of,  407 

,  carbonisation  of,  251 

,  composition  of,  407 

concrete  for  footpaths,  146 

-,   proportions  of,  318 


in  coal,  382 

-,  estimating,  381 


enrichers,  386 

gas,  267,  382 

lost  in  lime  purifiers,  271 

passing  to  purifiers,  269 

Sulphuretted  hydrogen,  267 

,  test  for,  375,  428 

Sulphuric  acid  for  hydrocarbons,  345 

,  normal,  345 

,  to  make,  405 

Sumpts  for  tanks,  202 
Superficial  measure,  43 
Superheated  steam,  394 
Superheaters  for  boilers,  176 

water  gas,  39 ) 

Supply  pipes  to  Argand  burners,  308 
Supporting  hydraulic  main,  159 
Surface,  heat  lost  by,  339 

in  scrubbers,  195 

Surveying  measure,  43 
Symbols  of  elements,  822 


TABLE  of  lighting,  209 
,  pressures  of  water  against  9, 

vertical  plane,  206 
Table  photometer,   the,  422 
Tabular  numbers,  correcting  by,  368,  422 

,  diagram  of,  366 

reference,  426 

Tangential  rollers,  effect  of,  211 
Tank  notes,  203 

sumpts,  202 

•   wall,  backings,  204 

walls,  202 

,  hoop  iron  in,  205 

— — =— ,  pressures  on,  203 


constituents,  406 

distillates,  406 

distilling,  results  of,  407 

firing,  advantages  of,  242 

for  painting,  280 

from  caking  coal,  407 

pavements,  317 

,  gas  from,  by  Peebles  process,  402 

,  heat  required  to  gasify,  402 

,  illuminating  compounds  in,  252 

in  hydraulic  main,  253 

scrubbers,  263 

on  coals  for  carbonising,  402 

process  at  Widnes,  252 

,  products  of,  381 

,  removal  of,  164,  255 

required  to  carbonise  coal,  242 

— ,  salts  in,  235 

seal,  gas  washed  by,  253 

separating  by  friction,  159 

,  steam  for  injecting,  242 

tanks,  165 

used  to  fire  retorts,  239 

,  yield  of  gas  from,  252 

Tees,  flanged,  dimensions  of,  118 
Tee  iron,  strength  of,  142 

or  steel  struts,  140 

,  weight  of,  91,  etc. 

Teeth  of  wheels,  proportions  of,  187 
Temperature  below  ground,  66 

best  in  condensers,  255 


,  correcting  for,  365 


in  ascension  pipes,  247,  254 

•- condensers,  254 

„ ,   cylinders,  168 

flues,  154 

•    foul  main,  160,  254 

~    generators,  393 

hydraulic  main,  254 


in  purifiers,  275 


INDEX. 


461 


Temperature  retorts,  254 

rooms,  308 

saturator,  405 


394 


pounds,  244 


carbons,  233 
373 


of  Bunsen  flames,  357 

—  changes  in  flames,  353 

—  combustion  of  gases,  332 

—  decomposition  of  water 

formation  of  sulphur  com 

furnaces,  to  find,  249 
gas  en  taring  purifiers,  26 
flames,  354 
fusion,  250 
production     of     hydra 

revivification    of    oxide 


301 


—   volatilisation  of  benzol 

water  in  scrubbers,  262 

to  convert  fuel  to  CO,  V40 

Temperatures,  colours  of  different,  248 

,   in  flues,  236 

gas  engines,  191 

—  mains,  300 

settings,  241 

Tensile  strain  on  side  plates,  225 
tank  sides,  205 

strength  of  mortar,  72 

Tension,  expansion  of  iron  by,  213 

of  ammonia  gas,  263 

aqueous  vapour,  326 

belts,  188 

Testing  benzene,  389 

,  calorific  power,  417 

• •  carburetting  for,  370 

coal,  381 

for  acetylene,  378 

gas  liquor  for  COg,  374 

with  Argand  burners,  367 

iron  and  steel,  112 

joints  with  soap,  292 

• lime,  372 

mains  in  district,  291 

pipes,  288 

slates,  79 

spent  oxide,  373 

station  meters,  Hartley's   notes 

valves,  292  ron   oi  q 

white  lead,  77  ion,  319 

Test  for  CO2,  378 

H2S,  375,  428 

Tests  for  napthalene,  256 
— pure  water,  261 

of  axles,  149 

coals,  251 

fire-bricks,  153 

Theory  of  formation  of  flames,  312 

light,  354 

photometers,  358 

Thermal  efficiency  of  engines,  166,  194 

unit,  166,  340 

Thickness  at  base  of  tank  walls,  205 

• of  ascension  pipes,  159 

* crown  sheets,  226 


Thickness  of  cylinder  in  tanks,  205 
engine  cylinders,  168 


•  hydraulic  cylinders,  151 

layers  in  purifiers,  201 

pipes  for  high  pressures,  289 

sheet  lead,  80 

glass,  77 


sheets  of  wrought-iron  tanks 
(diagram),  208 

side  sheets  of  gasholders,  212 

steam  pipes,  182 


tank  walls,  402 

•  tin  plates,  96 

11s,  72 


walls, 

web  plates  for  girders,  139 


Threads  for  bolts,  Whitworth,  126 
gas  pipes,  298 


screw,  125 


Three  lift  gasholders,  210 
Through  retorts,  155 
Tie-rods  in  coal  stores,  146 

,  proportions  of,  142 

to  benches,  154 

Timber,  81 

joists,  82 

,     safe  load  on,  86 

,    preserving,  81 

,    safe  load  on,  82 

,    seasoning,  81 

,    strength  of,  82 

Time  of  contact  in  purifiers,  197 

required  for  seasoning  timber,  83 

to  charge,  246 

make  sulphate,  405 


• to  start  water  .gas  plant,  394 

Tin  plates,  thickness  of,  96 

,  box,  sizes  and  weights,  97 

tubes,  weight  of,  124 

To  estimate  furnace  efficiency,  155 

—  save  fuel,  241 

—  test  heats  in  water  gas  plant,  393 
Ton,  decimals  of,  49 

Too  much  air  in  purification,  274 
Top  sheets  of  gasholders,  strains  on,  210 
Torsion,  resistance  to,  107 
Tower  scrubbers,  195 

,  effect  of  cold  on,  262 


foxicity  of  acetylene,  391 
Traction  resistance  on  roads,  147 
force  of  locomotives,  148 


Trains,  resistance  of,  149 
framcars,  gas  engines  for,  192 
framways  on  roads,  147 
Prap  sand  for  mortar,  73 
transmission  of  gas  through  pipes, 
heat,  175 


'ransverse  strength  of  plates,  140 
gravel  in  flues,  157 
'reads  and  risers  to  staircases,  80 
Mangles  in  guide  framing,  220 
'rigonometrical  terms,  41 
'roy  weight,  42 
'runk  mains,  292 
'russed  holder  curbs,  210 
Trussing  gasholders,  212 
Tubes,  block  tin,  weight  «f,  124 


462 


INDEX. 


Tuck  pointing,  74 

Turned  and  bored  pipes,  advantages  of, 

,  dimensions  of, 


WALLS  for  coal  stores,  146 
of  settings,  154 

tanks,  202 


200 

Turmeric  paper,  to  make,  342 
Twaddel,  264 
,  compared  with  specific  gravity, 

• ,  to  reduce  to  ounce  strength,  264 

TTNACCOUNTED  for  gas,  301 
U     Uneven  charging,  233 
Unions  for  gas  meters,  320 
Unit  of  heat,  166 
Uniting  lead,  100 
Units,  electric,  89 

of  light,  Harcourt's,  369 

Unloading  materials,  145 
Use  of  Portland  cement,  73 
sand  in  mortar,  72 

VACUUM  in  chimneys,  159 
waste  gas  flues,  241 

Value  of  acetylene,  390 

chalk,  270 

explosive  mixtures,  193 

• gas  in  sperm,  380 

spent  oxide,  269 

Values  of  different  quality  gases  for  eva- 
porating, 356 

gases  for  lighting  and  heating, 

356 

motive  power,  194 

Valves,  boxing  round  in  works,  165 

,  dimensions  of,  293 

for  hydraulic  mains,  161 

in  purifier  house,  201 

— ,  safety,  176 
—   —   to  condensers,  164 

,  testing,  292 

Van  Steenberg's  process,  399 
Vaporising  benzol,  temperature  for,  387 
Vapour  tension  of  benzene,  387 
Varnish,  covering  power  of,  77 
Velocity  in  exhaust  pipes,  182 

steam  pipes,  182 

of  diffusion,  279 

gases  in  chimneys,  179 

retorts,  234 

light,  356 

water,  151 

wind,  216 

Ventilating  flue,  chimney  as,  308 
Ventilation  notes,  311 

of  coals,  145 

photometer  rooms,  358 

retort  houses,  154 

Vertical  sheer  on  standards,  224 

stiffeners,  211 

Visibility  of  lights  at  distances,  310 
Vitiation  of  air  by  acetylene,   benzene, 

etliylene,  marsh  gas,  355 

• lights,  305 

Volume  of  one  pound  of  air,  327 
— sphere,  41 


,  thickness  of,  72 

to  fronts  of  benches,  155 

Warming  by  steam,  315 

secondary  air,  158 

Washers  and  scrubbers,  195 

for  petroleum  pipes,  397 

,  pressures  thrown  by,  196 

,  proportions  of,  102 

-,  weight  of,  103 


Washing  and  scrubbing,  262 

gas  with  mineral  oil,  325 


Waste  gases,  reduction  in  temperature  of, 

243 
Water,  absorptive  power  of,  374 

,  acetylene  absorbed  by,  391 

and  producer  gas  mixed,  398 

consumption   in   steam   engines, 


distribution  in  scrubbers,  195 
evaporated  by  fuels,  259 

furnaces,  155,  243 


261 


-,  evaporation  of,  332 

-,  expansion  and  weight  of,  333 

of  when  freezing,  337 


—  fall,  power  of,  88 

—  for  condensing  water  gas, 

—  from  carbon,  394 

—  gas  analysis,  392,  395 

,  blast  mains  for,  393 

,  blowers  for,  393 

,  CO2  in,  394 

carburettor,  393 

,  composition  of,  351 

condenser,  393 

,  cost  of,  399 

,  enriching  value  of,  396 

,  fuel  required  for,  394 

generator,  393 

,  oil  required  for,  394 

plant,  explosions  in,  394 

,  lighting  up,  394 

,  men  required  for,  393 

,  time  to  start,  394 

,  to  test  heats  in,  393 

production,  equation  of,  398 

purification,  396 

scrubber,  393 

,  steam  pressure  for,  393 

,  sulphur  compounds  in,  396 

superheater,  393 

with  anthracite  coal,  398 

—  heated  through  plates,  317 

—  in  ash-pans,  243 

hydraulic  mains,  253 

lime,  271 

oil  gas  tar,  396 

oxide,  267 

scrubber,  temperature  of,  262 

—  mixing  at  different  heats,  339 
— ,  pounds  heated  by  gases,  331 
various     sub- 


stances, 331 
,  power  of  absorption,  196 


INDEX. 


463 


Water,  pressure  of,  299,  323,  324 

produced  by  carbonisation.,  251 

,  pure,  tests  for,  261 

required  for  concrete,  74 

cooling  gas  engines,  192 

mortar,  73 

in  scrubbers,  196,  262 

to  slake  coke,  244 

lime,  201,  271 


seal  in  hydraulic  mains,  160 

,  specific  heat  of,  337 

vapour,  pressure  of,  327 

,  velocity  of,  151 

yielded  by  coal,  165 

Water-logged  earth  backing,  203 
Watertight  concrete,  207 
Water-tube  boilers,  coke  fired,  175 

condensers,  163 

Water-tubing,  weight  of,  297 
Watts,  electric,  89 

Web  plates  for  girders,  139 
Wedgewood's  pyrometers,  248 
Weight,  loss  of,  by  stacking  coal,  231 

of  aqueous  vapour,  327 

ascension  pipes,  160 

Bath  stone,  76 

bell  of  holder,  212 

block  tin  tubes,  124 

bolt  heads,  102 

brickwork,  67,  69 

cast-iron  pipes,  114,  281 

coke,  145 

composite  pipe,  123 

connections,  116, 

•  copper  nails,  98 

pipes,  124 

corrugated  iron,  98 

curb,  224 

dry  air,  328 

earths,  62 

• felt,  80 

• fire-bricks,  68 

fire-clay  blocks,  153 


Weight  of  sheet  braes,  124,  130 

sheet  glass,  77 

. iron,  124 

lead,  80 


slaked  lime,  272 

snow,  214 

sockets,  290 

square  foot  of  metals,  128 

tinplates,  box,  97 

various  coals,  145 

washers,  103 

water,  323 

wrought-iron  bridges,  141 

, tubes,  297 


yarn,  288 
York  paving,  76 
—  zinc  sheeting,  96 


Weights  and  measures,  42 

sizes  of  slates,  79 

,  comparative,  of  metals,  128 

Weldon  mud,  analysis  of,  274 

•   compared  with  oxide,  274 

constituents  of,  274 


Wet  coal  causes  napthalene,  256 

lime  for  purifying,  271 

meters,  particulars  of,  319 

Wetted  surface  in  standard  washers,  262 

Wetting  material  in  scrubbers,  262 

— ; oxide  with  ainmoniacal  liquor, 

Wicks  of  standard  candles,  360 
Wide  furnaces,  242 
Width  of  belts,  190 

retort  houses,  154 


-  gases,  to  obtain,  354 

gasholder  bell,  to  ascertain,  214 


Widths  of  rims  of  pulleys,  187 
Willesden  roofing,  80 
Wind  allowance  on  roofs,  79 

,  force  of,  215 

pressures  at  different  heights,  217 

• in  different  places,  216 

on  chimneys,  179 

different  areas,  217 

sphere,  219 

circular  objects,  218 


—  gasholders,  214 

(diagram),  221 

to  increase,  210 


half-round  iron,  130 

hoop  iron,  127 

•  lead  in  ordinary  joints,  288 

pipes,  -- 


• materials,  60 

mercury,  357 

mouthpieces,  160 

nuts,  102 

• oxide,  268 

—  pipes  (diagram),  120 

,    rule  for,  115 

puddle,  204 

rivet  heads,  106 

• rocks,  62 

• —  rolled  iron,  91 

— roof  materials,  78 

T — ; round    and   square   iron  and 

stael,  131 


—    of,  216 


,   velocity  of,  216 

Wire  gauges  in  decimals  of  1  inch,  89 
Wire  ropes  on  pulleys,  232 
,  strength  of,  109 


Wheels,  proportions  of  teeth,  187 
White  lead,  77 

,  effect  of  sulphur  on,  77 

,  setting,  280 

to  test,  77 


Whitworth  threads  for  screws,  125 

—  gas  pipes,  298 
Wood  changing  to  coal,  381 

charcoal,  gas  from,  252 

gas,  252,  387 

Wooden  joists,  137 

! troughs  for  services,  296 

I  Work  of  bricklayer,  72 
'  Workshop  area,  228 

floors,  loads  on,  82 

notes,  228 


.  Works  mains  in  wrought  iron,  165 
I  Wrought-iron  bridges,  weight  of,  141 


464 


INDEX. 


Wrought-iron  cylinders,  strength  of,  171 

• ,  effect  of  heat  on,  114 

girders,  notes  on,  132 

limits  of  weights  of,  140 
tanks,    thickness   of  (dia- 


gram), 208 


tube,  weight  of,  297 
works  mains,  165 


Wyatt's  rules  for  strains  in  gasholders, 
225 


TARN,  depth  of,  in  pipe  joints,  292 
required  for  joints,  288 

Year,  decimals  of,  47 


Yielding  of  gasholder  framing,  220 
Yield  of  carbide,  390 

ammonia,  262 

gas  from  tar,  252 

with  exhauster,  167 


tar  average,  407 

per  cent.,  255 

per  mouthpiece,  157 

square  foot  of  retorts,  234 


York  paving,  weight  of,  7( 
stone,  weight  of,  76 


17 1  NO  sheeting,  weight  of,  9(5 
/J slating  nails,  79 


THE   END. 


BBADBUBY,  AONEW..  &  CO.  LD.,  PB1NTEBB,  LONDON  AND   TONBBIDGE. 


ADVERTISEMENTS. 


G.  E. 


HH 


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